There are some punctuation marks that are used uniquely in either vertical writing mode
or horizontal writing mode. In this document, characters and symbols are treated as members of a character class, classified by their behavior for composition. Each class name is followed by class id, such as opening brackets (cl-01). Details are explained in 3.9 About Character Classes. The following are some typical examples:
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Full stops (cl-06) and commas (cl-07)
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In vertical writing mode, IDEOGRAPHIC FULL STOP "。" and IDEOGRAPHIC COMMA "、" are used for full stops (cl-06) and commas (cl-07).
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In horizontal writing mode, there are three conventions in choice of symbols for full stops (cl-06) and commas (cl-07):
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Using COMMA "，" and FULL STOP "．" (see [Fig.57]).
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Using COMMA "，" and IDEOGRAPHIC FULL STOP "。"
(see [Fig.58]).
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Using IDEOGRAPHIC COMMA "、"
and IDEOGRAPHIC FULL STOP "。"
(see [Fig.59]).
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(note 1)
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In horizontal writing mode, there are many cases of composition that mixes Japanese and Western text. The convention shown in (i) is a way to apply the same
comma and full stop
to both Western and Japanese texts for consistency, and is common in books on science and technology. The convention shown in (ii) was invented because in (i) FULL STOP "."
appears too small for Japanese texts and using IDEOGRAPHIC FULL STOP "。"
for period looks better. This convention has been adopted for Japanese official publications. (In the past, COMMA ","
and FULL STOP "."
were used for some official publications.)
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LEFT CORNER BRACKET "「", RIGHT CORNER BRACKET "」", LEFT DOUBLE QUOTATION MARK "“" and RIGHT DOUBLE QUOTATION MARK "”"
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In vertical writing mode, LEFT CORNER BRACKET "「"
and RIGHT CORNER BRACKET "」"
are used for quotations (see [Fig.60]).
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In horizontal writing mode, pairs of LEFT DOUBLE QUOTATION MARK "“"
and RIGHT DOUBLE QUOTATION MARK "”"
or pairs of LEFT SINGLE QUOTATION MARK "‘"
and RIGHT SINGLE QUOTATION MARK "’"
may be used in place of LEFT CORNER BRACKET "「"
and RIGHT CORNER BRACKET "」" (see [Fig.61]).
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(note 1)
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This is because LEFT CORNER BRACKET "「" and (especially) RIGHT CORNER BRACKET "」" may not look good in horizontal writing mode, but adoption of corner brackets for horizontal writing mode seems to be increasing.
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(note 2)
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Though LOW DOUBLE PRIME QUOTATION MARK "〟" and REVERSED DOUBLE PRIME QUOTATION MARK "〝" are similar to double quotation marks in appearance (see [Fig.62]) they are exclusively used for vertical writing mode and are not to be used in horizontal writing mode.
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(note 3)
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LEFT DOUBLE QUOTATION MARK "“"
and RIGHT DOUBLE QUOTATION MARK "”" are exclusively for horizontal writing mode and not to be used in vertical writing mode. Also, LEFT SINGLE QUOTATION MARK "‘" and RIGHT SINGLE QUOTATION MARK "’" are exclusively for horizontal writing mode and not to be used in vertical writing mode. However, in vertical writing mode, when Western characters (cl-27) are composed rotated 90 degrees clockwise, these quotation marks are sometimes used.
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LEFT SQUARE BRACKET "［", RIGHT SQUARE BRACKET "］", LEFT TORTOISE SHELL BRACKET "〔" and RIGHT TORTOISE SHELL BRACKET "〕"
LEFT TORTOISE SHELL BRACKET "〔" and RIGHT TORTOISE SHELL BRACKET "〕" are vertical variants of LEFT SQUARE BRACKET "［" and RIGHT SQUARE BRACKET "］", which are used in horizontal writing mode. Square brackets should be used in horizontal writing mode except for special
cases.
The positioning of punctuation marks (commas, periods and brackets) in a line proceeds as follows.
The character advance of commas (cl-07), full stops (cl-06), opening brackets (cl-01), closing brackets (cl-02) and
middle dots (cl-05)
is half-width (half em). But when those punctuation marks are placed side-by-side with ideographic (cl-19), hiragana (cl-15), or katakana (cl-16) characters, in principle, a given amount of space will be inserted before or after the symbols, which makes them appear as if they were intrinsically full-width (one em) (see [Fig.64]). Space is inserted before and after middle dots (cl-05). This principle makes the symbols consistent with ideographic (cl-19), hiragana (cl-15) and katakana (cl-16) characters in character width, and at the same time the space for punctuation helps to make the organization of text clearer. The space added before or after punctuation marks is subject, in principle, to line adjustment and may eventually be removed, except for that added after full stops (cl-06). (Details of line adjustment are discussed in 3.8 Line Adjustment).
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After commas (cl-07), a half em space is added, in principle.
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After full stops (cl-06), in the middle of a line, a half em space is added. At the end of a line, a half em space is added, in principle.
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Before opening brackets (cl-01), a half em space is added, in principle.
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After closing brackets (cl-02), a half em space is added, in principle.
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Before and after middle dots (cl-05), a quarter em space is added, in principle.
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(note 1)
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In font implementations, punctuation marks can be given a different character width, but it is expected that the font is capable of following the line composition rules explained here to produce the final result. For example, when opening brackets (cl-01)
and closing brackets (cl-02) are implemented with full-width size, it is possible that a minus half em space is inserted between adjacent closing brackets (cl-02) and opening brackets (cl-01)
(Some implementations prepare minus half em and quarter em spaces). In letterpress printing, it was also common practice to combine punctuation marks with a half-width body and half em spaces in order to make it easier to remove the space later for adjustment. Because of that, the types were picked up except for the punctuation marks at the type-picking phase, following the manuscript, and the punctuation marks were picked only when they were necessary in composing a page. Later, with the increasing adoption of Monotype machines, punctuation marks with a full-width body became popular and both full-width and half-width punctuation marks have been used, mixed together, since then.
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(note 2)
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Among opening brackets (cl-01)
and closing brackets (cl-02), LEFT PARENTHESIS "(", RIGHT PARENTHESIS ")", LEFT ANGLE BRACKET "〈" and RIGHT ANGLE BRACKET "〉"
are used to indicate supplementary explanations, and in that case their usage differs slightly from other opening brackets (cl-01)
and closing brackets (cl-02). To reflect the difference, there is an alternative convention to not append a half em space before or after the parentheses and angle brackets, and instead just set them solid (see [Fig.65]).
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The space usually added after IDEOGRAPHIC COMMA "、" and the space before and after KATAKANA MIDDLE DOT "・" are omitted, in principle,
for cosmetic reasons in the following cases.
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In vertical writing mode, ideographic numerals and IDEOGRAPHIC COMMA "、"
used as a decimal separator are set solid (as in the right line in [Fig.66]).
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(note 1)
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In vertical writing mode, ideographic digits used with IDEOGRAPHIC COMMA "、"
to represent an approximate number are expected to be set solid too (as in the right line in [Fig.67]).
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Ideographic digits and KATAKANA MIDDLE DOT "・"
representing a decimal point are set solid (as in the right line in [Fig.68]). In vertical writing mode, when KATAKANA MIDDLE DOT "・" is used as a member of unit symbols (cl-25) in unit symbols, grouped numerals (cl-24), and Western characters (cl-27) in mathematical and chemical formulae, before and after KATAKANA MIDDLE DOT "・" is set solid.
In cases where multiple punctuation marks, such as opening brackets (cl-01), closing brackets (cl-02), commas (cl-07), full stops (cl-06) and middle dots (cl-05), come one after the other, the following space adjustments are made for aesthetic reasons (see [Fig.69]). Note also that the half em and quarter em spaces added before or after punctuation marks, including the half em space after full stops (cl-06)
appearing in the middle of a line, are subject, in principle, to line adjustment and may eventually be removed, except for those added after full stops (cl-06). (See 3.8 Line Adjustment for more about line adjustment.) For more information about the positioning of closing brackets (cl-02), full stops (cl-06), commas (cl-07) and middle dots (cl-05) at line end, see 3.1.9 Positioning of Closing Brackets, Full Stops, Commas and Middle Dots at Line End.
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When closing brackets (cl-02)
come immediately after commas (cl-07)
or full stops (cl-06), remove the default half em space between them and, in principle, add a half em space after the closing brackets (see [Fig.69] (1)).
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When commas (cl-07)
come immediately after closing brackets (cl-02), remove the default half em space between them and, in principle, add a half em space after the comma. When full stops (cl-06) come immediately after closing brackets (cl-02), remove the default half em space between them and, in middle of a line, add a half em space after the full stop; at the end of a line, in principle, add a half em space after the full stop (see [Fig.69] (2)).
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When opening brackets (cl-01)
come immediately after commas (cl-07), in principle, add a half em space between them (see [Fig.69] (3)). When opening brackets (cl-01)
come immediately after full stops (cl-06) in the middle of a line, add a half em space between them. Note that when full stops (cl-06)
come in the bottom of lines, in principle, insert a half space after full stops (cl-06).
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When opening brackets (cl-01)
come immediately after closing brackets (cl-02), in principle, add a half em space between them (see [Fig.69] (4)).
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When opening brackets (cl-01) come immediately after other opening brackets (cl-01), set them solid and, in principle, add a half em space before
the first one (see [Fig.69] (5)).
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When closing brackets (cl-02) come immediately after other closing brackets (cl-02), set them solid and, in principle, add a half em space after
the last closing bracket (see [Fig.69] (6)).
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When middle dots (cl-05) come immediately after closing brackets (cl-02), in principle, add a quarter em space before the following middle dot
(see [Fig.69] (7)).
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When opening brackets (cl-01)
come immediately after middle dots (cl-05), in principle, add a quarter em space after the preceding middle dot (see [Fig.69] (7)).
The line adjustment rules shown above have been established because the default half em space before or after consecutive punctuation marks, or quarter em space before and after them, makes the line look sparse and doesn't make the line appear well-proportioned (see [Fig.70]).
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(note 1)
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Japanese composition is based on the design of full-width characters, but strictly following full-width based composition
sometimes produces an unbalanced appearance. In such exceptional cases, the appearance of the resulting composition must
be given higher priority than the full-width design principle. When and how to invoke such exceptional procedures has a direct
bearing on the quality of the text layout. In other words, it is a matter of how to resolve the conflicts between the principle
and the products of it.
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When starting a new line with opening brackets (cl-01) there are some patterns as shown in [Fig.71]. Note that the amount of line indent after the line feed (the first line indent of a new paragraph) is assumed to be a one em space across all the patterns.
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The first line indent after the line feed is set full-width (one em) and the next line after the first line break starts with no space (so-called tentsuki) (see [Fig.71] (1)).
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The first line indent after the line feed is set one and a half em and the next line indent after the first line
break is set to a half em (see [Fig.71] (2)).
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The first line indent after the line feed is set at a half em and the next line after the first line break is set tentsuki (see
[Fig.71] (3)).
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(note 1)
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Because the inherent character width of a bracket is half-width, [Fig.71] (1) can be explained as the result of applying the
principle that any line should start with no space. On the other hand, the principle represented by [Fig.71] (2) is to assume
that opening brackets should be always accompanied by the preceding half em space as if they were full-width and then apply the
same principle as in [Fig.71] (1). JIS X 4051 adopts the principle shown in (1) (the patterns shown in (2) and (3) are offered
as options) . The pattern shown in (3) was first invented in books such as novels, which use frequent line feeds and corner
brackets in dialogues, for which the first line indent with one em or one and a half em would create the appearance of too much space (then this pattern was accepted and adopted by general books). Major Japanese publishers who deal with literature, such
as Kodansha, Shinchosha, Bungei Shunju, Chuoh Kouronsha, and Chikuma Shobo, have adopted the pattern shown in (3). By contrast, Iwanami
Shoten and other publishers adopted the pattern shown in (1). Because Iwanami Shoten once adopted pattern (2) in vertical
composition, there used to be many examples of it, but few examples of (2) can be found today.
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(note 2)
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The first line indent of a new paragraph is full-width in principle. However, the following exceptions can be found.
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The most popular scheme is to set the first line indent of all new paragraphs to full-width. However, even if there is a paragraph break and the new line looks like the beginning of new paragraph, in contexts where the new line is a continuation of the preceding line, the new line is set tentsuki as shown in [Fig.72]. (There are books such as novels which adopt full-width line indent without exception.) Similarly, in horizontal writing mode, the line indent is set tentsuki where the new line continues the preceding line of a mathematical expression connected by conjunctions such as "therefore".
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When headings have no line indent, the first line indent of the first paragraph after the heading can be also
set tentsuki, for cosmetic reasons. However, it is not recommended to set the first line indent to tentsuki for all paragraphs,
because it would make paragraph breaks unclear.
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The dividing punctuation marks (cl-04) (QUESTION MARK "?" and EXCLAMATION MARK "!") should be full-width, and they are typeset as follows.
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Basically, add no space before dividing punctuation marks (cl-04) at the end of a sentence and add a one em space after them (see [Fig.73]). However when a closing bracket (cl-02) follows right after the dividing punctuation mark, add no space after the dividing punctuation
mark and add a half em space after the closing bracket (see [Fig.73]).
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When dividing punctuation marks (cl-04) at the end of a sentence reach the end of a line, apply the following rules (see [Fig.75]).
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If the line length is 13 character widths and a dividing punctuation mark (cl-04) occurs in the 12th character position, a one em space should be appended after it.
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If the line length is 13 character widths and a dividing punctuation mark (cl-04) occurs in the 13th character position, no
space should be appended after it. In addition, do not carry over the one em space usually appended after the dividing punctuation
marks to the line head of the next line; the line in this case should be set tentsuki.
The character width of hyphens (cl-03)
varies according to the type of hyphen. HYPHEN "‐"
should be quarter em width (i.e. one quarter of an em width), EN DASH "–"
and KATAKANA-HIRAGANA DOUBLE HYPHEN "゠"
should be half-width (a half em width), WAVE DASH "〜"
should be full-width. Basically there should be no space before and after hyphens (cl-03). However, a half em space should be appended, in principle, when opening brackets (cl-01) follow right after a hyphen (cl-03) and a quarter em space when middle dots (cl-05) follow a hyphen (cl-03).
In principle, no line should begin with closing brackets (cl-02), hyphens (cl-03), dividing punctuation marks (cl-04), middle dots (cl-05), full stops (cl-06), commas (cl-07), iteration marks (cl-09), a prolonged sound mark (cl-10), small kana (cl-11) or warichu closing brackets (cl-29) (line-start prohibition rule). Otherwise the line would have an odd appearance.
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(note 1)
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Not a small number of books adopt a less strict set of rules which allow IDEOGRAPHIC ITERATION MARK "々" (one of the iteration marks (cl-09)), prolonged sound mark (cl-10) and small kana (cl-11) to start a line.
There is another method whereby IDEOGRAPHIC ITERATION MARK "々" is replaced by a kanji character when it would otherwise be set at the head of a line. For example, 家 (at the end of a line) + 々 (at the head of the next line) will be changed to 家 (at the end of a line) + 家 (at the head of the next line).
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(note 2)
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There is yet another less strict rule that allows KATAKANA MIDDLE DOT "・" to start a line.
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(note 3)
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In the layout of newspaper text, dividing punctuation marks (cl-04) (QUESTION MARK "?" and EXCLAMATION MARK "!") are allowed to start a line. This is due to the fact
that the line lengths are shorter in newspapers. When the line is very short, there are fewer opportunities for inter-character
space adjustment, which makes it difficult to preserve the number of characters per line. It is thought
that this is the reason why the less strict set of line head wrapping rules was adopted in newspaper text layout.
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(note 4)
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The details of the line-start prohibition rules and line-end prohibition rules are described in Appendix B Spacing between Characters
as a complete table, following the description of character classes in 3.9 About Character Classes.
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In principle, closing brackets (cl-02), commas (cl-07)
or full stops (cl-06)
at the line end have a half em space after them (see [Fig.76]). This half em space can be deleted for line adjustment (for more about line adjustment, see 3.8 Line Adjustment). However, the possibilities are only half em space or solid. Other spaces, such as a quarter em space should not be used. In principle, the middle dot (cl-05)
character at the line end also has a quarter em space before and after, and is handled like a full-width character (see [Fig.76]). This quarter em space can also be deleted for line adjustment, namely middle dots (cl-05) can be set solid before and after (about line adjustment, see 3.8 Line Adjustment). However, in this case also, the only possibilities are quarter em space or solid setting. Other intermediate-sized spacing should not be used.
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(note 1)
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With regard to closing brackets (cl-02), full stops (cl-06), commas (cl-07) and middle dots (cl-05) at line end, the following processing is defined in JIS X 4051 (see [Fig.77]).
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(note 2)
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In the letterpress printing era, the following methods were common (see [Fig.78]).
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For full stops (cl-06), commas (cl-07) and closing brackets (cl-02), if possible, a half em space was preserved. Using a half em space was the general approach. For middle dots (cl-05), if possible, quarter em space was preserved. Using a quarter em space was the general approach.
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If the line length was not sufficient or too great and line adjustment processing became necessary (see below), the first priority was to replace the half em space after full stops (cl-06), commas (cl-07) and closing brackets (cl-02) with solid setting. The reason was that this was at the line end, and no problems would arise, even
though the half em space became set solid. The option of replacing the half em space after punctuation marks with a quarter em space, instead of removing the whole half em space was not used. That meant that there was the choice between either a half
em space after punctuation marks or solid setting. The second priority was to replace quarter em spaces before and after middle dots (cl-05) with solid setting.
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(note 3)
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In some DTP systems etc., after full stops (cl-06), commas (cl-07)
or closing brackets (cl-02)
at the line end, the line end is always set solid (see [Fig.79]).
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If the following characters and symbols appear in sequence there will be no line break between them. The reason is that these characters and symbols are to be handled as one unit.
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Between a sequence of EM DASH "—" characters (to be more specific, for a double dash, see [Fig.80]). Note that some systems implement HORIZONTAL BAR "―" with very similar behavior to EM DASH "—".
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(note 1)
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Other characters and punctuation marks before and after EM DASH "—" are set solid. However, in the following cases some space should be set between EM DASH "—" and other characters. As mentioned in the next note, HORIZONTAL ELLIPSIS "…", TWO DOT LEADER "‥", prefixed abbreviations (cl-12) and postfixed abbreviations (cl-13) behave similarly to EM DASH "—".
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Where closing brackets (cl-02) or commas (cl-07) are followed by EM DASH "—", a half em space is inserted between them, in principle. Also, in the middle of lines, where full stops (cl-06) are followed by EM DASH "—", a half em space is inserted between them. However, when full stops (cl-06) are placed at the end of a line a half em space is added after the full stops (cl-06).
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Where EM DASH "—" is followed by opening brackets (cl-01), a half em space is inserted between them, in principle.
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Where EM DASH "—" and middle dots (cl-05) are set side by side, a quarter em space is inserted between them, in principle.
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(note 2)
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A double dash is handled as one unit, hence a line break between them is forbidden. In letterpress printing, breaking of the double
dash was forbidden very strongly by the fact that the double dash was created as a double full body (so it was actually not possible
to break it). Nevertheless, if it was not possible to avoid a break, two EM DASH characters were used instead the double dash. That made it
possible to have a line break between them.
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Between sequences of HORIZONTAL ELLIPSIS "…"
or TWO DOT LEADER "‥"
(to be more specific, double HORIZONTAL ELLIPSIS "……" or double TWO DOT LEADER "‥‥").
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(note 1)
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In the letterpress printing era, double HORIZONTAL ELLIPSIS etc. was created as a sequence of HORIZONTAL ELLIPSIS. Hence, compared
to double dash, the line break between them was not so strongly forbidden.
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Between European numerals (see [Fig.82], [Fig.83], and [Fig.84].). European numerals indicate ranks via the position of a numeral.
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(note 1)
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It is possible to have a line break between ideographic numerals. Also it is possible to have a line break after IDEOGRAPHIC COMMA "、" used as a decimal separator or an indicator for approximate number, and KATAKANA MIDDLE DOT "・"
as a decimal point. However, the position between ideographic numerals and IDEOGRAPHIC COMMA "、" used as a decimal separator or an indicator for approximate number, and KATAKANA MIDDLE DOT "・" used as a decimal point is unbreakable. The reason is that the natural usage of ideographic numerals is to write them like "二百三十五", that is with inserted rank indicators (Explanation: "二" means "two", "百" means "hundred". "二百" means "two hundred". "三" means "three", "十" means "ten". "三十" means "thirty"."五" means "five". The complete sequence "二百三十五" means "Two hundred and thirty five".). Hence, it is not necessary to express rank via position. In contrast, line breaks are forbidden for European numerals, since it is necessary to express the rank via the position. Furthermore, if in vertical writing mode European numerals are placed in the appropriate direction side by side, they are used like the ideographic numerals, and it is possible to have a line break between them.
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(note 2)
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When writing European numerals, FULL STOP "." is used as a decimal point, COMMA "," or space is used as a rank indicator. Line breaks cannot occur before and after these characters (see [Fig.84]: the space before "4" expresses a rank).
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Between prefixed abbreviations (cl-12)
(YEN SIGN "¥"，DOLLAR SIGN "$"，CENT SIGN "¢" etc.) and the following arabic or ideographic numeral (see [Fig.82]). The reason is that such character sequences are to be handled as one unit.
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Between postfixed abbreviations (cl-13)
(PERCENT SIGN "%", PER MILLE SIGN "‰"
etc.) and the preceding European numeral
or ideographic numeral
(see [Fig.83]). The reason is that such character sequences are to be handled as one unit.
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(note 1)
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Some people think that it is appropriate to have a line break between the PERCENT SIGN "%" and the preceding arabic or ideographic numeral. The reason seems to be that PERCENT SIGN "%" has a high level of independence. Furthermore it is possible to have a line break between "0" and "パ" in cases like "50パーセント" (meaning "50 percent", where "percent" is written in katakana).
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Inter-letter space among Western characters (cl-27) in a word (or, sequence of letters, which it is not possible to hyphenate), or unit indicators (km, kg, mm etc.) in Latin letters (see [Fig.84]).
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(note 1)
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When using HYPHEN "‐" at the end of a line, it becomes possible to have a line break within Western characters (cl-27).
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(note 2)
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In this document, description of units with proportional Western characters, such as km and kg, are treated as unit symbols (cl-25).
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(note 3)
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In [Fig.84], there is a quarter em space between "4" and "k", because of the convention to insert a quarter em between unit symbols (cl-25) and following European numerals or Western characters (cl-27). It is permitted to break a line between "4" and "k". In this case, there is no quarter em space in either the head or the end of the line. Note that the space between "3" and "4" expresses a rank.
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Inter-letter space
among ruby letters, when composed as mono-ruby. Note that it is possible to break a line between base characters with mono-ruby (see [Fig.85]).
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Inter-letter space
among ruby letters or base characters, composed as group-ruby
(see [Fig.85]).
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(note 1)
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With ruby used for compound words (jukugo-ruby), a group of ruby characters is attached to each base character. It is possible to have a line break between such groups
of ruby letters and base characters (see [Fig.86]), however, a line break should not occur between ruby characters related to a given base character.
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Between a subscript or superscript and an adjacent base character (preceding or following) (see [Fig.87]), or between base characters with ornament characters, or between ornament characters themselves. The reason is that these character sequences are to be handled as one object.
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In order to create a correspondence between notes and the related main text, reference marks (aijirushi) are often added. Line breaks are not allowed before the reference mark or between letters of the reference mark itself (see [Fig.88]). The application of the no-line-break rule here is a matter of style.
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After warichu opening brackets (cl-28), which open warichu, or before warichu closing brackets (cl-29), which close warichu.
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A unit of furiwake. A unit of furiwake is handled as one object.
Methods of line adjustment processing are discussed in 3.8 Line Adjustment. However, since layout processing
of punctuation marks is one reason for the need for line adjustment processing, we will here introduce two main examples of cases where
line adjustment processing is necessary, and show adjustment examples (see [Fig.89]).
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The principal approach in Japanese composition is that with the exception of the last line of a paragraph, the length of all lines
is the same, so all lines are aligned. As explained before, the line length is set to be n-times the character size established for the kihon-hanmen. Hence, as long as only full-width
characters are used, all lines have the same length (see (1) at [Fig.89]).
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In [Fig.89]
at (2), there is an IDEOGRAPHIC COMMA "、"
followed by a LEFT CORNER BRACKET "「", and the complete space taken by the two characters is one and a half em. That means that the line overshoots or runs short of the edge of the kihon-hanmen by a half em. To restore a uniform line length, line adjustment is applied as shown at (3) in [Fig.89]. The half em space overshoot or shortage is recovered by reducing inter-character space to a quarter em before the LEFT CORNER BRACKET "「" and after the RIGHT CORNER BRACKET "」".
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At (4) in [Fig.89], the 15th character is an opening bracket (cl-01). This should not appear at the line end. Ideally, a full
width space reduction would be applied, and the character "前" on the second line would be moved onto the first line in the
15th position. In that way, the problem could be avoided. However, in this example a full-width space reduction is not possible,
so line adjustment processing is applied as shown at (5) in [Fig.89]. The opening bracket (cl-01) is moved to the second line, and line adjustment by inter-character space expansion is applied. That means that space is inserted in the first line at places where it is allowed.
There are a lot of examples of Japanese text in which Western and/or Greek letters are mixed among Japanese letters. Examples
are as follows:
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Using one Latin letter as a symbol for something, like "A" and "B".
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Using a Western word in a Japanese context, like "editor".
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Using acronyms of things and organization names, like "DTP" and "GDP".
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Writing Western book titles and authors in lists of referred books with original spelling.
Latin letters are also used in itemized lists and numbering of headings, as well as symbols for units, symbols for chemical elements,
and mathematical symbols. As can be judged from these examples, mixtures of Latin letters among Japanese letters are in daily use
in Japanese composition.
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(note 1)
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There are some examples which include whole Western paragraphs in Japanese documents. However, there are few ordinary books that
include such paragraphs. There are a lot of examples of textbooks for foreign languages,
in which one or more Western paragraphs are followed by annotations in Japanese language. Also, there are some examples in treatises and journals, which contain whole Western paragraphs.
|
|
(note 2)
|
In vertical writing mode, symbols for units are usually described with katakana (cl-16), such as センチメートル (centimeter) or センチ(abbreviation of centimeter in katakana, "senchi"). In horizontal writing mode, the International System of Units (SI) is usually used, such as "cm".
|
|
(note 3)
|
The treatment of mixtures of Japanese and Western characters is also described in JIS X 4051 4.7.
|
In horizontal writing mode the basic approach is to use proportional Western fonts ([Fig.90]). For European numerals, both half-width fonts and proportional fonts are used. Note that Western word space (cl-26) is a one third em space, in principle, except at line head, line head of warichu, line end and line end of warichu. Western word space (cl-26) at line head, line head of warichu, line end and line end of warichu, is set solid.
|
(note 1)
|
As shown in [Fig.91], there are some examples of Western full-width fonts used in horizontal Japanese typesetting, this usage is
not recommended, for cosmetic reasons.
|
|
(note 2)
|
Usually, in horizontal Japanese text, fonts are used with European numeric glyphs that are easy to balance and harmonize with Japanese
fonts. Considering line adjustment, the use of fonts with half-width numeric glyphs is recommended. There are some cases of Japanese fonts with half-width glyphs for European digits.
|
|
(note 3)
|
There are two choices for including glyphs of Latin letters and numerals in Japanese and Western mixed text compositions.
One way is to use the glyphs for Western characters built into the same Japanese font. The other is to combine an independent
Western font for Western characters with a Japanese font for Japanese characters. (Example: [Fig.92] is composed using proportional glyphs for Latin letters and numerals included in Ryumin R-KL. [Fig.93] is composed with Ryumin R-KL for Japanese characters and Times New Roman for Latin letters and numerals.)
|
As explained in 2.3.2 Major Differences between Vertical Writing Mode and Horizontal Writing Mode, there are three different styles for setting Latin letters and European
numerals in vertical writing mode:
-
Setting Latin letters and/or European numerals one by one in inline direction with Japanese characters (see [Fig.94]). This style is typically adopted when composing a single Latin letter or European numeral between the adjacent Japanese
letters. Full-width glyphs are specified for Latin letters and European numerals in this style.
-
Setting Latin letters and/or European numerals rotated 90 degrees clockwise in vertical text mode ([Fig.95]). This style is usually adopted when Latin letters compose a word or sentence. Proportional fonts are specified for
characters in this style, as in horizontal writing mode (or half-width fonts for European numerals).
-
Setting Latin letters and/or European numerals in tate-chu-yoko (horizontal-in-vertical setting, see [Fig.96]). Tate-chu-yoko layout is usually adopted when dealing with a two-digit number in European numerals, or a combination of
two or three Latin letters, the length of which is equal to the default size of the line in paragraph direction or longer
than that just to an acceptable extent. (A combination of two or three Latin letters may be rotated 90 degrees clockwise rather
than set it in tate-chu-yoko layout.) Proportional glyphs (or half-width glyphs for European numerals) are used
for characters in tate-chu-yoko layout.
|
(note 1)
|
Acronyms, such as "GNP", and abbreviations like "Web", are usually set one by one, character-wise in normal orientation (see
[Fig.97]). However, there are some cases where acronyms and abbreviations are rotated 90 degrees clockwise (see [Fig.98]).
|
|
(note 2)
|
The ideographic numerals were traditionally used in vertical writing mode instead of European numerals. (Road numbers
and car registration numbers were examples of a couple of exceptions). However, the more newspapers and other publications have been adopting European numerals in vertical writing mode, the more the use of tate-chu-yoko layout for European numerals has also been increasing.
|
When full-width
and fixed-width
Western characters or European numerals are set in vertical writing mode
as "quasi" Japanese characters, inter-character spaces
between these characters and hiragana (cl-15), katakana (cl-16)
or ideographic characters (cl-19)
are set solid, similar to ordinary ideographic characters (cl-19)
(see [Fig.99]). Also, in principle, when full-width and fixed-width Western characters or European
numerals are set after full stops (cl-06), commas (cl-07)
or closing brackets (cl-02), or before opening brackets (cl-01), insert a half em space after commas (cl-07)
or closing brackets (cl-02), or before opening brackets (cl-01). In addition, in these cases, insert a half em space after full stops (cl-06). When full-width and fixed-width Western characters or European
numerals are set before a full stop (cl-06), comma (cl-07)
or closing bracket (cl-02), or after an opening bracket (cl-01), the inter-character space before the full stop, comma or closing bracket, or after the opening bracket is set solid.
|
(note 1)
|
In this document, full-width and fixed-space Western characters and European
numerals are treated as members of the ideographic characters (cl-19)
class. Accordingly, when KATAKANA MIDDLE DOT "・"
appears before or after full-width and fixed-space Western characters and Western numerals, in principle, a quarter em space is inserted between KATAKANA MIDDLE DOT "・" and Western characters or Western numerals. However, when KATAKANA MIDDLE DOT "・"
is used as a ranking symbol between Western numerals, in principle, it is set solid, like ideographic numerals.
|
|
(note 2)
|
The details of ideographic characters (cl-19), including full-width and fixed-width Western characters and European
numerals, are described as a complete table in Appendix B Spacing between Characters, following 3.9 About Character Classes.
|
To set strings as tate-chu-yoko (horizontal-in-vertical setting), first set from left to right using solid setting, then align the whole string to the center of the vertical line ([Fig.101]). When hiragana (cl-15), katakana (cl-16)
or ideographic characters (cl-19)
are set before/after tate-chu-yoko, the inter-character space is set solid. In principle, when tate-chu-yoko is set after a comma (cl-07)
or closing bracket (cl-02), or before an opening bracket (cl-01), a half em space is inserted. In addition, when tate-chu-yoko is set after a full stop (cl-06)
in the middle of a line, a half em space is inserted. When a full stop (cl-06) is set at the end of a line, a half em space is inserted after it, in principle. When tate-chu-yoko is set before full stops, commas or closing brackets, or after opening brackets, the inter-character space is set solid.
Composition rules for Western characters, Western text and European numerals, set rotated 90 degrees clockwise in vertical writing mode, and horizontal writing mode, are as follows:
-
A sequence of Western characters in a Western word should not be broken across a line-break, except where hyphenation is allowed.
-
When line adjustment is done with line adjustment by inter-character space reduction, Western word space (cl-26) is used as first priority. Also, when line adjustment is done with line adjustment by inter-character space expansion, Western word spaces are used as first priority.
-
When line adjustment by inter-character space addition is used, inter-character spaces within Western words and European numerals are not used for expansion.
-
Inter-character space, between hiragana (cl-15), katakana (cl-16) or ideographic characters (cl-19) and Western characters or European numerals, is a quarter em space (see [Fig.102]). The issue as to whether the quarter em space can be used for line end adjustment or not is discussed in 3.8.2 Reduction and Addition of Inter-Character Space and 3.8.4 Procedures for Inter-Character Space Expansion.
-
In the following cases, a quarter em space is not inserted (see [Fig.103]).
-
At the start of a line, there is no space before Latin characters or European numerals. At the end of the line,
there is no space after Latin characters or European numerals.
-
In the case where Latin characters and European
numerals follow a comma (cl-07)
or closing bracket (cl-02), or are followed by opening brackets (cl-01), in principle, a half em space is inserted. In the case where Latin characters and European numerals follow a full stop (cl-06) in the middle of a line, a half em space is inserted. When the full stop (cl-06) is set at the end of a line, in principle, a half em space is inserted after the full stop (cl-06).
-
In the case where Latin characters and European numerals are set before a full stop (cl-06), comma (cl-07) or closing bracket (cl-02), or after an opening bracket (cl-01), the inter-character space is set solid.
Ruby is a small-sized, supplementary text attached to a character or a group of characters in the main text. A run of ruby text,
usually attached to the right of the characters in vertical writing mode or immediately above them in horizontal writing mode, indicates
the reading or the meaning of those characters (see [Fig.105]). The characters in the main text that are annotated by ruby are called "base characters". Kana characters are often used for ruby to indicate how to read kanji characters; this is known as ruby annotation or as "furigana".
|
(note 1)
|
Societal change in the use of kanji when composing Japanese and changes in the use of ruby implementations in text layout methods
have been affecting the usage of ruby itself. Ruby was not very popular while the Touyou Kanji Table (当用漢字表) (the list of kanji characters for everyday use, issued by the
Government on November 16, 1946) was in effect because, in principle, it discouraged the use of furigana in its 'directions for use' section. The Jouyou Kanji Table (常用漢字表) (the list of kanji characters in common use, issued by the Government to replace the Touyou Kanji Table on October
10, 1981) has changed the scope of the list. (The Touyou Kanji Table defined the list of all kanji characters that can be used for
any documents, while the Jouyou Kanji Table was designed to be a 'reference guide' for the use of kanji to compose contemporary
Japanese for general use in society.)
For example, the preface of the Jouyou Kanji Table states that one may consider the use of 'furigana (annotations to indicate pronunciation)' when the text appears too
difficult to read. This is why the use of ruby has been increasing today. The use of ruby is common in magazines and books,
and even newspapers have begun to use ruby these days.
|
|
(note 2)
|
The specification of ruby composition was first introduced in the second revision of JIS X 4051, which was further revised
in 2004 to add jukugo-ruby, katatsuki-ruby and the dual ruby composition with which two distinct runs of ruby are attached
to the same base characters (4.12 Ruby Composition).
|
In terms of annotation, ruby has several purposes as described below.
Depending on the purpose and/or the function of the ruby, there are different ruby composition methods (the details of the composition
methods will be provided in the later sections).
-
PURPOSE: Ruby annotation with kana (usually hiragana) to provide readings of kanji characters.
There are two types of ruby for this purpose depending on the type of base character:
-
Add one or more hiragana (cl-15) or katakana (cl-16) ruby character to indicate the reading (Japanese onyomi or kunyomi) for each base ideographic character (cl-19) (see [Fig.106]).
This method, attaching one or several hiragana or katakana characters for each base ideographic character, is called mono-ruby.
-
In the Japanese writing system, compound words (jukugo) occasionally appear, usually constructed with a couple of kanji characters. There are two different methods of attaching ruby letters to base kanji characters for these compound words.
-
Mono-ruby. Ruby letters are attached to each base kanji character, similarly to the previous section (see [Fig.107]).
|
(note 1)
|
In [Fig.107], there is a quarter em space between the base characters "凝" and "視". So when this line happens to appear in the middle of a paragraph, there needs to be some line adjustment processing.
|
-
Jukugo-ruby. Pronunciation is indicated for each base character, but the positioning takes into account the fact that together they make up a compound word (see [Fig.108]). The intention when using jukugo-ruby is to handle the kanji phrase as one object.
|
(note 1)
|
There is no difference between [Fig.107]
of mono-ruby and [Fig.108]
of jukugo-ruby, when the
number of ruby letters for each base kanji character is one or two. When the mono-ruby approach is adopted, the inter-character space between base kanji characters can be expanded for line adjustment (in [Fig.107], the inter-character space between "鬼" and "門", or, "方" and "角" can be expanded). When the jukugo-ruby approach is adopted, line adjustment cannot be applied to the base kanji characters.
|
|
(note 2)
|
The following examples show the relationship between ruby letters and base kanji characters.
|
Example of mono-ruby:
|
"凝+(ぎよう)" "視+(し)"
| |
Example of jukugo-ruby 1:
|
"凝+(ぎよう) 視+(し)"
| |
Example of jukugo-ruby 2:
|
"(凝視)+(ぎよう/し)"
|
|
|
(note 3)
|
Books commonly adopt kana-based jukugo-ruby for kanji compound words. However, due to technical difficulties for rendering jukugo-ruby in machine-assisted text layout, the adoption of kana-based mono-ruby is increasing. For example, newspapers do not use jukugo-ruby, and study aids generally use mono-ruby because it is considered more important to show the readings of each kanji character for students than to be concerned about the beauty of the layout.
|
|
(note 4)
|
Multiple kanji compound words can form one compound phrase. In this case, there are two ways to attach ruby, i.e. attaching ruby
to the compound phrase as a whole, or to each word which forms the compound (see [Fig.109]). Similarly, a Japanese personal name consists of a given name and a family name, which together form a compound of a full
name, and it is an editorial decision whether to attach two runs of ruby, one each for given name and family name, or to attach the
full ruby text to the compound which represents the reading of the full name.
|
|
(note 5)
|
In most cases, the reading of a kanji compound word is just a concatenation of the readings of each individual kanji character, but some phrases
have their own native readings (known as jukuji readings), which cannot be derived from the readings of each character. Attaching
ruby to those phrases, which are usually sequences of two or three kanji characters, is essentially the same as attaching ruby in katakana to kanji and/or kana base characters (see [Fig.110]).
|
-
PURPOSE: Ruby annotation that annotates a kanji or kana word with kana to provide its meaning, together with it's reading. In terms of ruby layout, attaching ruby text to a single character in kanji or kana is essentially the same as attaching the reading to a kanji character (e.g. attaching ruby text "バザール", 'Bazaar', in kana to a kanji character "市" is just like attaching the
reading "いち" to that character). When attaching ruby text to a run of base text consisting of two or more characters in kanji and/or kana, the ruby text needs
to be positioned as if it corresponds to the annotated text itself, no matter how the ruby characters are distributed
across each base character.
The most typical example of this is attaching ruby text to a kanji compound word to indicate a corresponding loan word
in katakana (see [Fig.110]).
The use of ruby text of this kind is on the increase in proportion to the growing need for translations and loan words.
This type of ruby, namely ruby letters that are attached to two or more base characters as one object, is called group-ruby. Group-ruby and it's base characters are unbreakable, because of their behavior as one object (it is possible to break a line in the middle of the base characters where jukugo-ruby is in use).
|
(note 1)
|
Having said that, the layout of ruby text to a single kanji character is not entirely the same depending on the use of ruby, and may differ according to
whether it is for indicating the reading or the meaning. In fact, the katatsuki, one of ruby layout per character which will
be described in the later section, does allow the nakatsuki layout for those ruby which indicate meaning.
|
-
PURPOSE: Ruby annotation, usually with katakana characters, to indicate the reading or the meaning of a Western word used in
base text (see [Fig.112]).
There are opposite cases where a synonymous Western word in Latin characters is attached as a ruby annotation to a Japanese
word in kana or kanji (see [Fig.112]). These cases are less used than a and b, however they are quite common in study guides, translated books and travel guides.
-
PURPOSE: Ruby annotation using kanji for a base text word in hiragana. This is called furikanji, and is very rarely found.
Hereafter, mainly the usage of (a) and (b) will be explained.
|
(note 1)
|
There is no difference in the positioning of ruby text whether attaching ruby characters in kana to a Western word in Latin characters or attaching ruby in Latin to a Japanese word in kanji or kana. The ruby text in either case should be positioned relative to a run of base text to be annotated as in b). However, there is a difference in cases where the lengths of the base text and the ruby text are different. When the length of a ruby text in kana or kanji is shorter than the corresponding base text, the ruby text is, in general, stretched by adding inter-character spaces between ruby characters, and when the length of a ruby text in kana or kanji is longer than the corresponding base text, the base text is, in general, stretched by adding inter-character spaces between base characters, so that the ruby and base text look similar in length (see [Fig.107]). On the other hand, no inter-character space will be added to any ruby or base text in Latin characters no matter how different the ruby and base text look in length (see [Fig.112]). Details will be explained later.
|
There are several methods of choosing how to attach ruby annotations to which base characters.
-
'General-ruby' is the method of attaching ruby annotations to all base characters in kanji.
-
'Para-ruby' is the method of attaching ruby annotations to only those base characters in kanji for which readings are
difficult.
|
(note 1)
|
The 'para-ruby' method is further divided into the method of attaching ruby annotations regardless of multiple occurrences of
the same base kanji character, and the method of attaching ruby annotations to only the first instance of the same base
kanji character. Furthermore, the latter method has several variations in counting the first instance for the entire book,
each chapter, or each spread, etc.
|
Note that ruby should be attached to all kanji characters in a compound word, to reflect the unitary nature of the text. To attach ruby to only some of the kanji characters in a compound word is not recommended (see [Fig.113]).
The character size of ruby characters is, in principle, the half size of the base characters (see [Fig.114]).
The 'one-third-ruby' characters are used on rare occasions to attach three ruby characters to one full-width kanji character. One-third-ruby for vertical layout has the dimension of the half of the base character in width and the one third in height. Those
for horizontal writing mode have the dimension of half of the base characters in height and one third in width (see [Fig.115]).
When ruby is attached to twelve point or larger base characters (usually used for headings), the size of the ruby letter is generally smaller than half the size of the base characters, considering the proportion of the sizes
of base characters and ruby. When all is said and done, these cases are very rare.
|
(note 1)
|
There are cases where the body size is twelve points in books designed for infants or aged people. In these cases, the
size of ruby can be six points, exactly the half size of the base characters.
|
|
(note 2)
|
When the size of base characters is very small (for e.g. smaller than seven points), ruby which is half the
size, will be even more small and illegible. In such cases where the size of base characters is very small, ruby is not
a suitable method of annotation. In those cases, consider other annotation methods such as adding the reading in parenthesis immediately
after the base character.
|
|
(note 3)
|
Slightly different from the question of the size of ruby, there is a question of whether or not small kana (cl-11) characters should be used
in ruby annotations. Because the size is so small, there was no choice of using small kana in letterpress printing.
Today there are cases where small kana are used in ruby annotations, but taking legibility into consideration, these cases should be
limited to those where accurate readings are needed, such as for proper nouns.
|
In principle, ruby is attached to the right of base characters in vertical writing mode, and above in horizontal writing mode.
In some special cases, ruby can be seen to the left of base characters in vertical writing mode, and below in horizontal writing mode, but this is very rare.
There are cases where two kinds of ruby are attached, one to either side of the base characters, one for readings and the other for
meanings (see [Fig.117]). This is also very rare.
In the following sections, the ruby composition methods will be explained on the assumption that the size of ruby is half the size of the
base characters, and they will be attached to the right in vertical writing mode and above in horizontal writing mode. First we look at
the basic composition rules of mono-ruby, group-ruby and jukugo-ruby, then the rules of positioning of ruby with respect to
those characters which come before and after the base characters, and finally the composition rules at the line head
and at the line end.
When mono-ruby characters are Japanese, they are set solid. If mono-ruby characters have their own character widths such as
Western characters or European numerals, they are set according to their own widths and then the ruby text is placed so that its center
matches that of its base character. There are more variations depending on the combination of the base character
and ruby text and accordingly various composition rules have been invented, which will be explained with examples.
When attaching two kana ruby characters to a single base character, the lengths of the ruby text and the base text are the same and they are positioned as shown
in [Fig.118].
When attaching a single ruby character to a single base character, there are two ways of positioning the ruby character.
-
In vertical writing mode, attach a ruby character so that its vertical center matches that of the base character (see [Fig.119]).
In horizontal writing mode, attach a ruby character so that its horizontal center matches that of the base character (see
[Fig.119]).
This positioning of a ruby character is called 'nakatsuki' (center-alignment).
-
In vertical writing mode, attach a ruby character so that the top of its virtual body is aligned with the top of that of the base
character (see [Fig.119]). This positioning of a ruby character is called 'katatsuki' (top-alignment).
For horizontal writing mode, 'katatsuki' should not be adopted. If a ruby character is attached so that the left-edge of its virtual
body is aligned with the left-edge of that of the base character, it would result in the loss of the center of balance, which
doesn't look good (see [Fig.120]).
|
(note 1)
|
Katatsuki alignment was commonly used in the letterpress printing era, but today the adoption of nakatsuki alignment is increasing
even in vertical writing mode. However, there is still an opinion favoring katatsuki alignment, because it is familiar and
readable.
|
When attaching more than three hiragana ruby characters to a single base character, the ruby characters are set solid. In this
case, where the length of a ruby text is longer than that of its base character, positioning of the ruby text depends
on which alignment has been adopted for a single ruby character. There is another issue: how to maintain the spatial balance
of the ruby characters hanging over those characters which are not related base characters. The adjustment of inter-character
spacing for those characters which come before and after the base character will be explained in a later section.
-
When nakatsuki alignment is adopted for a single ruby character, position a ruby text so that its vertical center is aligned
with that of its base character in vertical writing mode (see [Fig.121]). In horizontal writing mode, position a ruby text so that its horizontal center is aligned with that of its base character
(see [Fig.121]).
-
When katatsuki alignment is adopted for a single ruby character, there are two methods, as follows.
-
Position the ruby text so that its vertical center is aligned with that of its base character (see [Fig.121]).
-
Depending on the type of script of the adjacent characters to the base character, and the number of ruby characters, a decision
is made about whether ruby hangover is allowed on the character before its base character, or on the character after, or
on both adjacent characters. At break-even situation, the hangover is usually on the character after its base character (see [Fig.122]).
|
(note 1)
|
The terms katatsuki and nakatsuki were originally used for ruby alignment only when a single ruby character is attached
to a single base character. However there are cases where the meaning is stretched so that the terms can be used when
more than three ruby characters are involved. We use the terms katatsuki and nakatsuki with their original meaning throughout
this document.
|
|
(note 2)
|
The preference for the choice of hanging the ruby over the character after its base character is due to the preference
to avoid adjustment of inter-character spacing between base characters and their adjacent characters, which was common
in letterpress printing.
|
For mono-ruby, base characters and adjacent ruby characters are handled as one object, and internal line-breaks are prohibited.
When the length of a sequence of base characters (number of characters * advance-width of each character) and that
of the ruby text are the same, each text is set solid and the center of both texts are aligned with each other (see
[Fig.123]).
When the length of the ruby text is shorter than that of its base characters, set the base text solid and stretch the ruby text by adding a certain amount of inter-character space between each adjacent ruby character, so that both texts balance each other. To be more specific, where 2 units of inter-character space are used between ruby characters, add 1 unit of space between the start of the base text and the start of the ruby text, and between the end of the ruby text and the end of the base text. This will give a balanced appearance, and is the method specified in JIS X 4051 (see [Fig.124]). Another way is to first align the leading characters for both the base text and ruby text and the ends of both trailing characters, and then add the same amount of inter-character space between the rest of the ruby characters (see [Fig.125]).
|
(note 1)
|
In letterpress printing, there were not many choices for adjustment of inter-character space between ruby characters. Therefore,
depending on the number of characters in the base text and its ruby text, the choice was whether to add a certain amount of space
before the leading ruby character and after the trailing character, or not. In the former case it had been said that for 2
units of inter-character space between each adjacent ruby characters, adding 1 unit of the leading and trailing space would
give a balanced appearance.
|
|
(note 2)
|
When the length of the ruby text is far shorter than that of the base text, the method specified in JIS X 4051 could
result in space twice the size of a ruby character for the leading and the trailing space, which might give a misleading appearance.
Therefore, a criterion for deciding whether or not to adopt the method of JIS X 4051 is to see if the amount of the leading and the trailing
space exceeds the full-width size (or up to 1.5 times the size) of a ruby character (see [Fig.126]).
|
When the length of the ruby text is longer than that of the base characters, balance the base characters with the ruby text by setting the ruby text solid and adding a certain amount of inter-character space between each adjacent base character. To be more specific, for 2 units of inter-character space, add 1 unit of space between the start of the ruby text and the start of the base text, and between the end of the base text and the end of the ruby text, as specified in JIS X 4051 (see [Fig.127]). Another way is to first align the start of both the leading characters and the end of the trailing characters, and then add a certain amount of inter-character space between each adjacent base character (see [Fig.128]).
For group-ruby, base characters and adjacent ruby characters are handled as one object, and internal line-breaks are prohibited. Also, for an object constructed with base characters and adjacent ruby characters it is prohibited to insert additional spaces between each character for line adjustment.
If the number of ruby characters are two or less for each kanji character which participates in a kanji compound word (or jukugo), then for each run of ruby text associated with each base character, compose ruby characters as described in 3.3.5 Positioning of Mono-ruby with Respect to Base Characters (see [Fig.129]).
If there is any kanji character in a given kanji compound word
which needs more than three ruby characters, the jukugo-ruby layout cannot be used. In this case, attach the ruby text
to the kanji compound word as a whole. The available methods include the layout as specified in JIS X 4051, which is similar to the group-ruby method described in 3.3.6 Positioning of Group-ruby with Respect to Base Characters
(see [Fig.130]), and layout decided by the phonetic structure of the kanji compound word
and the type of script of the adjacent characters (see [Fig.131]). The latter method can be used unless a run of ruby text for the base character hangs over another base character more than a full character width (or one and a half times the full-width) of a ruby character.
|
(note 1)
|
There are often cases where the jukugo-ruby consists of one ruby character followed by three ruby characters, and vice versa, for
a kanji compound word of two base characters. If the mono-ruby layout were chosen for these cases, it would look like as shown
in [Fig.132], which wouldn't be very beautiful.
|
Jukugo-ruby can be split into two lines at the boundary of each unit of ruby text attached to one kanji character. When a kanji compound word consists of two characters, each unit will be processed using the mono-ruby method. When dividing a compound word that consists of three kanji, use the mono-ruby method for the first kanji character and use the jukugo-ruby method for the remaining
two kanji characters, and vice versa. In order to maintain the correspondence of each kanji to its ruby annotation, the layout
of the ruby may be different after the division (see [Fig.133]).
Note that jukugo-ruby and its base characters cannot be the subject of inter-character space expansion for line adjustment.
When the length of any ruby text is shorter than that of the base characters, the main text can be just set solid because
there is no need for any adjustment of the inter-character spacing between base characters and
their adjacent characters in the main text.
When the length of the ruby text is longer than that of the base characters, the method of composing the main text depends on how
much the ruby text hangs over the kanji or kana characters, or punctuation marks, which are adjacent to the principal
characters. The following are the general rules (see [Fig.135] and [Fig.136]). They were established especially in order to avoid misreading and to maintain the beauty of the layout.
-
Ruby text shall not hang over the ideographic characters (cl-19) adjacent to the base characters.
-
When the adjacent character is a hiragana (cl-15), katakana (cl-16), prolonged sound mark (cl-10) or small kana (cl-11), the ruby text may overhang the character up to the full-width size of the ruby characters.
-
The ruby letter may go over the base characters and overhang the half em spaces which are inserted after closing brackets (cl-02), full stops (cl-06)
or commas (cl-07), set before the target ruby object, up to the full-width size of a ruby letter. Also, the ruby letter may go over the base characters and hang over the half em spaces which are inserted before opening brackets (cl-01), set after the target ruby object, up to the full -width size of a ruby letter. Note that when the spaces are reduced for line adjustment, the room for ruby letter overhang is also compressed. (For example, if the space is a quarter em in the base character size, the ruby letter can overhang by a half em in ruby letter size.)
-
When the adjacent character is an inseparable character (cl-08), the ruby text may overhang the character up to the full-width size
of a ruby character.
-
When the adjacent character is one of the middle dots (cl-05), the ruby text may overhang the middle dots, in principle, up to the full-width
size of a ruby character. But if there is any reduction of space before and after the middle dots as a result of the line
adjustment, the amount of the extension shall be up to the amount of space after the middle dots plus 1/2 a ruby character size when the middle dots are set before the ruby object, or the space before the middle dots plus 1/2 a ruby character size when the middle dots are set after the ruby object.
-
When the adjacent character is one of the closing brackets (cl-02), the ruby text may go over the principal characters up to the full-width size of a ruby character. Note that the overhang must not go beyond the closing bracket itself.
-
When the adjacent character is a comma (cl-07) or full stop (cl-06), the ruby text may go over the base characters and overhang the comma or full stop up to the full-width
size of a ruby character. Note that the overhang must not go beyond the comma or the period itself.
-
Also, when the adjacent character is one of the opening brackets (cl-01) before the ruby object, the ruby text may go over the base characters and hang over the opening brackets up to the full-width size of a ruby character. Note that the overhang must not go beyond the opening brackets..
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(note 1)
|
There is an opinion that it is not good style to hang ruby characters over opening brackets (cl-01), especially LEFT CORNER BRACKET "「" and RIGHT CORNER BRACKET "」". When this opinion holds, there are two possibilities. One is not allow ruby characters to overhang the opening brackets (cl-01). The other is allow ruby characters to overhang the opening brackets up to 1/2 the size of a ruby character.
|
|
(note 2)
|
JIS X 4051 classifies katakana characters and kanji characters in same class. Accordingly, in JIS X 4051 it is prohibited for ruby characters to overhang adjacent katakana characters.
|
|
(note 3)
|
There is another variation that allows ruby text to overhang any ideographic characters (cl-19), hiragana (cl-15) or katakana (cl-16) up to the full-width
size of a ruby character (see [Fig.137]).
|
|
(note 4)
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There is a further variation that does not allow ruby text to overhang any ideographic (cl-19), hiragana (cl-15) or katakana (cl-16) characters (see
[Fig.138]).
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When the line head starts with ruby annotated text where the ruby text length is shorter than that of the base characters,
compose the text so that the first base character is aligned with the line head. Similarly, when ruby annotated
text ends at the line end and the ruby length is shorter than that of the basic characters, compose the text so that the
last basic character is aligned with the line end.
When the line head starts with ruby annotated text where the ruby text length is longer than that of the base characters, compose the text so that the first ruby character
which overhangs the base text is aligned with the line head, and vice versa (see [Fig.139]). Alternatively, there is a variation by which the text is composed so that the first base character is aligned with the line head,
and vice versa (see [Fig.140]).
When aligning the first base character to the line head and the last base character to the line end, ruby text
is not allowed to extend beyond the hanmen or the area of the column. If it does, the following adjustments should be considered
in positioning base characters and ruby characters.
-
Mono-ruby at the line head: Make adjustments so that the top of the ruby text is aligned with that of the base
characters (see [Fig.140]).
-
Mono-ruby at the line end: Make adjustments so that the bottom of the ruby text is aligned with that of the last base
character (see [Fig.140]).
-
Group-ruby at the line head: Make adjustments so that the top of the ruby text is aligned with that of the first base character, and add the same amount of inter-character spacing between the base characters and between the end of the last base character and the end of the last ruby character after the last base character (the method specified in JIS X 4051) (see [Fig.141]).
-
Group-ruby at the line end: Make adjustments so that the end of the ruby text is aligned with that of the last base character and add the same amount of inter-character space between the base characters and the space between the start of the base text and the start of the ruby text (the method specified in JIS X 4051) (see [Fig.141]).
-
Jukugo-ruby at the line head or at the line end: Make the same adjustments as described in (c) or (d) for the group-ruby.
-
Jukugo-ruby at the line head: Make adjustments so that the top of the ruby text is aligned with that of the first base
character. A run of ruby characters for a base character may overhang the adjacent base characters of the same kanji compound word, up to the full-width size (or one and a half of it) of a ruby character. If the extension should go
beyond the limit, just force the ruby text out of the base characters, or make a further adjustment by adding inter-character
space between the base characters.
-
Jukugo-ruby at the line end: Make adjustments so that the end of the ruby text is aligned with that of the last
base character. A run of ruby characters for a base character may overhang the adjacent base characters of
the same kanji compound word, up to the full-width size (or one and a half of it) of the ruby characters. If the extension should
go beyond the limit, just force the ruby text out of the base characters, or make a further adjustment by adding
inter-character space between the base characters.
-
Jukugo-ruby split across two lines: jukugo-ruby can be split across two lines, with one part at the line end and the other at the line head.
In the case of a compound word with two kanji characters, it is as the same as dealing with one kanji character with a mono-ruby
text at the line end and the other kanji character with another mono-ruby text at the next line head. In the case of a phrase
with three kanji characters, handle one kanji character with mono-ruby text and the remaining two kanji characters with jukugo-ruby,
and vice versa. The layout of one kanji character with mono-ruby text will be composed by method (a) or (b) described above.
The layout of two kanji characters with jukugo-ruby text will be composed by method (f) or (g) above.
Emphasis dots (also known as bouten or side dots) are symbols placed alongside a run of kanji or kana characters to emphasize
the text.
|
(note 1)
|
There are many ways to emphasize a run of text in Japanese composition. Besides attaching emphasis dots, one may emphasize
a certain run of text by selecting a different typeface (for example, Mincho face for normal text and Japanese gothic face for emphasis),
a different color (for example, turning to red for emphasis), by enclosing the text within brackets (for example, LEFT CORNER BRACKET "「" and RIGHT CORNER BRACKET "」"
or LEFT ANGLE BRACKET "〈" and RIGHT ANGLE BRACKET "〉"), by drawing a line alongside the text (or bousen, underlining the text), and so on. It is an editorial decision
which emphasis method to adopt. Selecting a different typeface and enclosing text within brackets are generally used and
popular emphasis methods. Attaching emphasis dots is not very common but one of the long-established and traditional methods typically
used in kanbun composition (classic Chinese text).
|
|
(note 2)
|
In practice, emphasis dots are not used for commas (cl-07), full stops (cl-06), opening brackets (cl-01) or closing brackets (cl-02).
|
Composition of emphasis dots is as follows (see [Fig.142]).
-
The character size of emphasis dots is the half size of the base characters to be emphasized.
-
Emphasis dots are attached to the right of the base characters in vertical writing mode, or above them in horizontal writing mode. The center of emphasis dots is aligned with that of the base characters.
-
There are many symbols that could be specified for use as emphasis dots. SESAME DOT "﹅"
in vertical writing mode and BULLET "•"
in horizontal writing mode are those used for emphasis dots in general.
Warichu (inline cutting note) is a type of inline notation, where two lines of small characters are inserted into the text. Warichu divides a line into two sub lines. The frequency of use of the inline cutting note is not so high. However,
the inline cutting note is very important for study guides, travel guides, reference books, encyclopedias and manuals, because it is very effective for inserting notes at the point in the text where they are needed (see [Fig.143]). Inline cutting note is usually used in vertical writing mode. It is very infrequently used in horizontal writing mode.
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(note 1)
|
JIS X 4051 specifies inline cutting note in 4.16 "Handling of inline cutting note".
|
Character size for an inline cutting note depends on the character size established for the kihon-hanmen. Usually, around six point size is used (see [Fig.143]).
The space between adjacent lines in an inline cutting note is zero, that is to say, there is no line gap between them (see [Fig.144]).
As shown in [Fig.144], an inline cutting note usually has two lines, and is surrounded by LEFT PARENTHESIS "(" and RIGHT PARENTHESIS ")" characters that are double the size of the characters in the inline cutting note itself. There is no space between the surrounding text and parentheses for the inline cutting note.
Symbols, like opening brackets (cl-01), closing brackets (cl-02), commas (cl-07) and full stops (cl-06)
are also used in inline cutting note text. In such cases, the handling of such symbols is the same as for the main text.
In vertical text, the horizontal width of the inline cutting note area is wider than the width of a kihon-hanmen line. The horizontal centers of the kihon-hanmen line and inline cutting note area are aligned. The line gap used to establish the kihon-hanmen should not be affected by the horizontal
width of the inline cutting note area. In other words, the line gap for the kihon-hanmen needs to be designed wider than usual in preparation for the use of the inline cutting note. Warichu is used also in horizontal text, however it is not so common, and usually occurs only in study guides and encyclopedias.
The length of the two lines of the inline cutting note should be as near as possible the same. When the inline cutting note can be set in one kihon-hanmen line, the whole inline note text should be broken at a position where line breaking is permitted, and where the two resulting lines are as close as possible to the same length. The length of the second line should not be longer than the length of the first line. Note that the same line breaking rules are used as for basic text (see [Fig.145]).
When an inline cutting note will not fit on a single kihon-hanmen line, it will wrap onto the following line, and will be set as shown in [Fig.146] or [Fig.147].
|
(note 1)
|
Normally, an inline cutting note is short, and will therefore fit on a single kihon-hanmen line. There are cases where the note wraps onto the following line, but it is rare that it extends over three or more of the kihon-hanmen lines. If the note is too large, other styles of notation should be considered.
|
A paragraph, a section of a document which consists of one or more sentences to indicate a distinct idea, usually begins on
a new line. For the related line head indent at the beginning of paragraphs (in JIS 4051, this is called the "paragraph line head
indent") the following methods are available. The amount of space used for the indentation is, in principle, one em space using the character size in the paragraph.
|
(note 1)
|
The definition of line head indent at the beginning of paragraphs is provided in JIS X 4051, sec. 4.17 "paragraph appearance
processing". Note that "paragraph appearance processing" includes "line head indent", "line end indent" and "indent" in general.
|
|
(note 2)
|
The layout processing for opening brackets (cl-01) and closing brackets (cl-02) in the case of full-width line head indent at the beginning of paragraphs,
is described in this document, 3.1.5 Positioning of Opening Brackets at Line Head.
|
-
Line head indent at the beginning of paragraphs is applied to all paragraphs. Nearly all books and magazines make use of
this method (see [Fig.148]).
|
(note 1)
|
In the case of written conversational text followed by, for example, "she said", if the conversational part is bounded by LEFT CORNER BRACKET "「" and RIGHT CORNER BRACKET "」" and the "she said" text appears after a line-break, the conversational text and the "she said" text are considered to be one continuous phrase. Hence, there is no line head indent at
the beginning of the "she said" phrase, after the conversation part, i.e. so-called tentsuki (see [Fig.149]). When you have a (mathematical) formula on a separate line in horizontal writing mode, and a following line containing text such as "will be" there is also no line head indent at the beginning of the paragraph. On the other hand, there is also an approach in novels etc., where the first line indent is applied to paragraphs (see [Fig.150]).
|
-
Line head indent at the beginning of paragraphs is not applied for any paragraph at all, and the tentsuki position is used
(see [Fig.151]). There are examples of this method being used in certain books and magazines for the sake of styling, but this is rather hard
to read.
-
In principle, line head indent is applied at the beginning of a paragraph. However, a paragraph immediately following a tentsuki-set heading is also set tentsuki, so that the beginning of the heading and the paragraph are aligned (see [Fig.152]). In some books and magazines this method is applied to text in horizontal writing mode.
On the other hand, for example with itemization, there is also the method that indents the second and following lines of the paragraph (see [Fig.153]). This is the so-called "questions and answer" (Q&A) form. It has the effect that numbers (if used) stand out.
|
(note1)
|
The definition of itemization is provided in JIS X 4051, sec. 8.4 "itemization processing".
|
The line head indent is the indentation of the line head by a fixed amount, starting from the line head side of the hanmen (in the case of one column) or of the column area (in the case of several columns). In contrast, the indentation of the line end position by a fixed amount, starting from the line head, is called line end indent.
There are examples of line head indent for quotations in separate lines (see [Fig.154]) or for headings in separate lines. Line end indent is used, for example, for headings or for quotations in separate lines.
|
(note 1)
|
For quotations on separate lines, there are the following approaches: either (a) the character size is the same as for the main text, and the difference from the main text is expressed only by the line head indent; or (b) the character size is made smaller than that of the main text. The former approach is applied frequently. With this approach, the line head indent is often set at double the normal character size of the main text. If large quotations are inserted frequently, there is also an approach that uses a full-width line head indent with an empty line inserted before and after the quotation. The approach where characters are made smaller than the main text is not discussed in this document (but may be addressed in a future version of this document, see 4.2 Notes).
|
|
(note 2)
|
Line head indent is also applied for endnotes, but this is not discussed in this document (it may be addressed in a future version, see 4.2 Notes).
|
The Japanese "single line alignment method" is a process for setting alignment for a run of text that is shorter than a given line length. This method is frequently used for headings and poems. The following methods are available (see [Fig.155]).
|
(note 1)
|
The single line alignment method is defined in JIS X 4051, sec. 4.18 "Single Line Alignment Processing".
|
-
Centering: The space between adjacent characters is, in principle, set solid. (If space is needed between Japanese text and western text, before opening brackets (cl-01)
and after closing brackets (cl-02), that space is inserted based on the table in Appendix B Spacing between Characters.) Also, if there is an explicit instruction to insert spaces, such spaces are inserted. If there is not solid setting but a fixed space between characters, this is used; the amount of space at the line head and line end is made equal, and the center of the character sequence is unified with the center of the line.
-
Line head alignment: The space between adjacent characters is, in principle, set solid. (If space is needed between Japanese text and western text, before opening brackets (cl-01)
and after closing brackets (cl-02), that space is inserted based on the table in Appendix B Spacing between Characters.) Also, if there is an explicit instruction to insert spaces, such spaces are inserted. If there is not solid setting but a fixed space between characters, this is used; the start of the character sequence is unified with the line head, and if the line is not full, the line end is kept empty.
-
Line end alignment: The space between adjacent characters is, in principle, set solid. (If space is needed between Japanese text and western text, before opening brackets (cl-01)
and after closing brackets (cl-02), that space is inserted based on the table in Appendix B Spacing between Characters.) Also, if there is an explicit instruction to insert spaces, such spaces are inserted. If there is not solid setting but a fixed space between characters, this is used; the end of the character sequence is unified with the line end, and if the line is not full, the line head is kept empty.
-
Even spacing distribution: The space between adjacent characters is, in principle, set solid. (If space is needed between Japanese text and western text, before opening brackets (cl-01)
and after closing brackets (cl-02), that space is inserted based on the table in Appendix B Spacing between Characters.) Also, if there is an explicit instruction to insert spaces, such spaces are inserted. In addition, using the space made available during line adjustment processing, equal character spacing is applied where possible (or character space reduction is applied where possible). The start of the character sequence is aligned to the position of the line head, and the end of the character sequence to the position of the line end.
|
(note 1)
|
Several justification methods are applied for positioning of headings or items of tables. For example, centering is often used for headings
in horizontal writing mode, taking the left-right balance is taken into account. However, there are also
examples of line head alignment.
|
|
(note 2)
|
Even spacing distribution is often used for printing Haiku in separate lines (see [Fig.156]).
|
The intent of widow adjustment of paragraphs is to avoid that the last line of a paragraph contains less than a
given number of characters. This is also called "widow" processing.
|
(note 1)
|
Widow adjustment of paragraphs is defined in JIS X 4051, sec. 4.20 "Widow Adjustment of Paragraphs".
|
|
(note 2)
|
Widow adjustment of paragraphs is not regarded as very important in Japanese composition. However, care is taken to avoid cases
such as a single character in the last line of a paragraph (often this is tolerated), or - even more extreme -
just one character on a page just before a page break or a new recto (see [Fig.157]).
|
Superscripts and subscripts are small letters associated with base characters, and typically used to indicate SI unit symbols, or
used for mathematical or chemical formulae.
|
(note 1)
|
Superscripts and subscripts are described in JIS X 4051 sec.4.13.
|
Superscripts and subscripts are usually set after the base character, with some exceptions for chemical formulae (which appear before the base character). They should be set solid.
For examples of superscripts and subscripts see [Fig.168].
In this document, superscripts and subscripts and their base characters are handled as ornamented character complex (cl-21) characters.
JIS X 4051 specifies the character size and the block direction positioning of superscripts and subscripts alongside the base character to be implementation definable parameters. However it is recommended that the size of superscripts
and subscripts are around 60% of the base character, depending on the size of the base character.
It is prohibited to break lines within an ornamented character complex (cl-21) sequence. Also, it is prohibited to use inter-character spacing within an ornamented character complex (cl-21) sequence for line adjustment.
|
(note 1)
|
In vertical writing mode, characters with superscripts or subscripts, that is ornamented character complex (cl-21) characters, are rotated 90 degrees clock-wise. If the length
of the sequence is short enough, the sequence can be set as tate-chu-yoko.
|
|
(note 2)
|
When both the superscript and the subscript follow the base character, usually the subscript is set first and set solid, followed by the superscript set with solid space. For chemical formulae sometimes both superscript and subscript are set vertically in the same position with respect to the base character, and with solid space between them and the base character.
|
Furiwake is a typesetting style for setting multiple phrases or sentences in in the middle of a line. Furiwake is also used to indicate
options (see [Fig.169]). Study guides, manuals and reference books sometimes use furiwake. In many furiwake styles, multiple lines are indicated with
opening brackets (cl-01) and closing brackets (cl-02), etc.
Furiwake is usually done as follows (see [Fig.170]). In this document, the lines which combine to make the furiwake are called furiwake-gyou.
-
The character size of the furiwake-gyou is usually the same as that of the base paragraph. Sometimes, the furiwake-gyou
is a little bit smaller than the size of the base paragraph. Sometimes, the font style of the furiwake-gyou is different typeface the
style of the base paragraph.
-
In the same furiwake block, the top positions of all the furiwake-gyou lines are aligned.
-
The line length of the furiwake block is the line length of the longest furiwake-gyou. However, it is permitted to indicate
the length of the furiwake block, and break the furiwake-gyou lines. In this style, the start positions of the broken lines should be
explicitly indicated. When there are line break marks in the furiwake-gyou, the line is broken in the indicated places. In this style,
the start positions of the wrapped lines are aligned to the first line. The space between wrapped lines should be set solid.
-
The line-feed space of each furiwake block should be explicitly indicated.
-
The center line of the furiwake block should be aligned with the center line of the main text.
-
When the furiwake block is enclosed by opening brackets (cl-01) and closing brackets (cl-02), etc. the width of brackets should be the same as
the width of the furiwake block.
-
One furiwake block should be set per base text line. One furiwake block should not be extended across multiple base text lines.
The size of the line-feed space of the paragraph which contains the furiwake block, should be explicitly indicated.
The space should be decided by considering the content of the furiwake block, and may therefore differ from the size of the line-feed space of kihon-hanmen.
In general, the width of the furiwake block is larger than the width of an inline cutting note block. However, unlike in the case of the inline cutting block, the whole furiwake block should
be set inside of the kihon-hanmen, or a column of the kihon-hanmen Setting a furiwake block that extends beyond the border of the kihon-hanmen
is prohibited.
In cases such as lists of names of Japanese people, the length of some part of the text may be explicitly defined. In such cases, different numbers of characters are set, using adjustment of the inter-character spacing, so that they are all aligned to the same length. This is called jidori processing
(see [Fig.171]).
Sometimes, in horizontal writing mode, text in running heads (with the exception of chapter and section numbers) are set using jidori processing. For example, three to six characters are set in a 7 character space (based on the size of the characters in the running head (see [Fig.172]). Two characters are set in a 6 character space to avoid too much space. Seven characters are set solid in a seven character space, and eight or more characters are set solid in a space of eight or more characters. This rule can be applied to other numbers of characters, such as five, six and eight.
Jidori processing should be done as follows:
-
The length for the jidori processing should be defined as a whole number of full-width characters at the size defined for the surrounding text.
-
The jidori text should be adjusted using spacing between characters so that the sides of the text are aligned at the defined length. The following, however, should be set solid:
-
Positions where line breaks are prohibited: inter-character spaces between European numerals; between two EM DASH "—" characters; between two TWO DOT LEADER "‥" characters; between two HORIZONTAL ELLIPSIS "…" characters; and so on. These sequences should be treated as a single block.
-
Where Western word space (cl-26) or full-width ideographic space (cl-14) are inserted, the add same space as for other inter-character spaces to the value of the Western word space or the full-width ideographic space.
-
If there is only one character, it should be aligned to the left of the jidori block.
Math symbols and math operators, such as EQUALS SIGN "=", APPROXIMATELY EQUAL TO OR THE IMAGE OF "≒", PLUS SIGN "+" and MINUS SIGN "−" are commonly used not only for scientific and technical documents but also for ordinary books. In the Japanese composition system, there are two different groups of math symbols, which are each treated differently. So in this document math symbols are classified into two different classes; math symbols (cl-17) and math operators (cl-18).
|
(note 1)
|
The members of the math symbols (cl-17) and math operators (cl-18) classes are described in 3.9 About Character Classes. Also, the handling of inter-character spaces between these math symbols and adjacent characters is described in Appendix A Character Classes as a complete table, in accordance with the concept of character class, described in 3.9 About Character Classes.
|
|
(note 2)
|
Because the math symbols, such as SQUARE ROOT "√", INTEGRAL "∫" and GREEK CAPITAL LETTER SIGMA "Σ", are not frequently used in common books, the handling of these math symbols is considered to be out of scope for this document. Also, mathematical and scientific notations like numerical formulae are out of scope for this document.
|
Composition rules for math symbols (cl-17) and math operators (cl-18) are as follows:
-
The width of math symbols (cl-17) and math operators (cl-18) is full-width, i.e. one em (see [Fig.174]).
-
The inter-character space between math symbols (cl-17)
or math operators (cl-18)
and before and after adjacent characters, such as grouped numerals (cl-24), Western characters (cl-27), and ornamented character complex (cl-21)
in one line is set solid (see [Fig.174]). However, when the top and/or the bottom of the mathematical formula is grouped numerals (cl-24)
or Western characters (cl-27), the space between ideographic characters (cl-19), hiragana (cl-15)
and katakana (cl-16)
is quarter em space.
-
When math formulae or chemical formulae are set in one independent line, the inter-character space between math symbols (cl-17) and adjacent grouped numerals (cl-24), Western characters (cl-27) and ornamented character complex (cl-21) is quarter em. Also, when math formulae or chemical formulae are set in an individual line, the inter-character space between math operators (cl-18) and adjacent grouped numerals (cl-24), Western characters (cl-27) or ornamented character complex (cl-21) is set solid.
-
A line can be broken between math symbols (cl-17) or math operators (cl-18) and adjacent grouped numerals (cl-24), Western characters (cl-27) or ornamented character complex (cl-21).
Line adjustment processing is applied where inter-character adjustments are needed to bring the line end into the correct alignment, e.g. because of line wrap or other reasons. Within a paragraph, lines are created by separating character sequences at places where line breaking is not prohibited. Except for the end
of the last line of a paragraph, it is necessary to set the head
and end
of each line at predicable,
aligned positions. For the last line of the paragraph, it is still necessary to set the head at the aligned position, however the line end may not aligned to the other alignment position. To achieve this, only inter-character spacing indicated in the table of Appendix B Spacing between Characters, or explicitly chosen spaces, are inserted, and other inter-character spaces are set solid.
|
(note 1)
|
In Japanese composition, there is no concept corresponding to the Western "ragged right (flush left)", "ragged left (flush right)", or "ragged center". In Japanese composition, especially common book composition, usually only "justification" is applied. Note that, in Western composition, "justification" is usually applied for only word spaces. In Japanese composition, it is applied for not only Western word space (cl-26)
but also in several other places as explained in following text.
|
|
(note 2)
|
Usually, the last line of a paragraph needs no adjustment. However, when the last line of a paragraph is a little bit longer than the line length, inter-character space reduction is applied for opening brackets (cl-01)
, closing brackets (cl-02) and at other places, if possible.
|
|
(note 3)
|
There is another adjustment processing, besides line adjustment, called "single line alignment". Single line alignment is applied to align a run of the text that is shorter than a given line length to designated positions. Details are explained in 3.9 About Character Classes.
|
There are various reasons for line adjustment processing. Examples of the most important ones will be given below.
-
Mixed use of characters and symbols (e.g. grouped numerals (cl-24) or Western characters (cl-27)) where not all characters are full-width
(see [Fig.178]).
-
Sequences of punctuation marks. For example, a sequence of a closing bracket (cl-02)
and a full stop (cl-06)
takes one and a half em spaces together (see [Fig.179]). However, if an opening bracket (cl-01)
follows immediately after the full stop, these punctuation marks will need two em spaces together. Hence, no adjustment is needed to correctly align the line end (see [Fig.179]).
-
Mixtures of characters with different sizes (see [Fig.180]).
|
(note 1) |
In cases where additional information like page references, explanations of terminology, etc. appear within brackets, sometimes the character
size is a level smaller than the character size established by the kihon-hanmen.
|
-
Cases where line head wrapping, line end wrapping or unbreakable character sequences should not be broken (see [Fig.89]).
Line adjustment processing targets places with a predefined space or solid setting. Methods for line adjustment are as follows.
-
Line adjustment by inter-character space reduction. This means that a half em space is reduced after commas (cl-07) or closing brackets (cl-02), or before opening brackets (cl-01), and Western word space (cl-26) is reduced
within a defined limit.
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Line adjustment by inter-character space expansion. Line adjustment by inter-character space expansion means expanding inter-character space for line adjustment, where inter-character space is allowed to be extended up to a defined limit, such as for Western word space (cl-26) or other places where it is not prohibited to extend inter-character space.
Normally line adjustment by inter-character space reduction is preferred. Only when there are no spaces that can be reduced is line adjustment by inter-character
space expansion applied. The reason for the preference of line adjustment by inter-character space reduction comes from
the thinking that characters in solid setting should not have more inter character space, if at all possible.
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(note 1)
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Line adjustment by hanging punctuation is a method of avoiding line head wrap of full stops (cl-06) and commas (cl-07). This method is not formally defined in JIS X 4051, however JIS
X 4051 does provide explanatory material about it.
Line adjustment by hanging punctuation is a method which is only applied to full stops (cl-06) and commas (cl-07). These touch the hanmen and
are set in a place outside the defined line length (see [Fig.181]). This is also applied, for example, in books, in order to avoid the addition of inter character space and maintain solid setting. However,
line adjustment by hanging punctuation is not an appropriate method for dealing with a mixture of Japanese and Latin script text, since the latter principally does not apply line adjustment by hanging punctuation. In addition, there is another argument against
line adjustment by hanging punctuation. Originally it was a method used in letterpress printing, to make the task of line
adjustment easier. Furthermore, as shown at the end of line 1 and 5 of [Fig.181], if possible the full stops (cl-06) or commas (cl-07) are placed at the line end (the 18th position). In DTP there are examples of hanging punctuation
like in line 3, but this may be regarded as unnecessary processing.
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For line adjustment by inter-character space reduction decisions must first be made about
the preferred order in which reduction processing options
are applied, and the maximum amount of space reduction needed. Inter-character space reduction is processed with following priorities.
-
Western word space (cl-26), which is usually one third em,
is reduced by equal amounts, to leave a minimum of a quarter em space between words. The same space reduction is applied to all spaces on the target line at the same time.
-
The half em space after closing brackets (cl-02),commas (cl-07)
and full stops (cl-06)
at the end of a line, is deleted and set solid.
-
The quarter em spaces both before and after the middle dots (cl-05) are deleted and set solid.
-
The quarter em space before or after middle dots (cl-05), in the middle of a line, is reduced equally with proportional character size as far as solid setting.
-
The half em spaces before opening brackets (cl-01) or after closing brackets (cl-02)
or commas (cl-07),
in the middle of a line, are reduced equally with proportional character size, as far as solid setting.
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(note 1) |
With the exception of the line end position, the half space after full stops (cl-06) should not adapted, since it plays an important role as a sentence separator.
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(note 2) |
Commas (cl-07)
fulfill different roles to opening brackets (cl-01)
and closing brackets (cl-02). Hence, there are examples where it is preferred to reduce the half em space before or after brackets, rather than to reduce the half em space after commas. |
|
(note 3) |
The reduction of the half em space before opening brackets (cl-01)
or after closing brackets (cl-02)
and commas (cl-07)
up to solid setting is regarded as too much reduction. Hence, there are examples where the maximum amount of space reduction is up to quarter em space. |
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The quarter em space between Japanese text (hiragana (cl-15), katakana (cl-16) and ideographic characters (cl-19)) and Latin script text (grouped numerals (cl-24), Western characters (cl-27) and unit symbols (cl-25)), is reduced equally
with proportional character size, as far as one eighth em space.
In JIS X 4051, the space after closing brackets (cl-02), commas (cl-07) and middle dots (cl-05) at the end of a line are set solid, and the space after commas (cl-07) at the end of a line is set to a half em. Accordingly, JIS X 4051 defines the priority of processing as follows:
-
Western word space (cl-26), which is usually one third em, is reduced by equal amounts, to leave a minimum of a quarter em space between words.
-
The quarter em space before and after middle dots (cl-05)
is reduced equally with proportional character size as far as solid setting.
-
The half em spaces before opening brackets (cl-01)
and after closing brackets (cl-02)
or commas (cl-07), are reduced equally with proportional character size as far as solid setting.
-
The quarter em spaces between Japanese text (hiragana (cl-15), katakana (cl-16)
and ideographic characters (cl-19)) and Latin script text (grouped numerals (cl-24), Western characters (cl-27)
and unit symbols (cl-25)) are reduced equally with proportional character size, as far as a 1/8th em space.
As with line adjustment by inter-character space reduction, for line adjustment by inter-character space expansion at first
the order of processing and the maximum amount of space to be added are defined. In JIS X 4051, the following processing order
is defined.
-
Western word space (cl-26), which is usually one third em, is added equally with proportional character size up to a maximum of a half em size for each space.
-
The quarter em space between Japanese text (hiragana (cl-15), katakana (cl-16) and ideographic characters (cl-19)) and Latin script text (grouped numerals (cl-24), Western characters (cl-27) and unit symbols (cl-25)) is increased equally
with proportional character size, up to half em space (or one third em space).
-
For places which do not fall under (a) or (b) and which do not have bunrikinshi, space is added equally with proportional character
size up to a quarter em space.
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In addition to the adaptation in the manner of (a), (b) and (c), in cases where such processing is not possible, space is added
equally with proportional character size, with the exception of places which require bunrikinshi.
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(note 1) |
JIS X 4051 provides a definition in addition to (d). This says that it depends on each layout processing system whether inter-character space should be added equally. This includes the space between Western characters (cl-27).
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(note 2) |
The detail of the places where space expansion is possible for line adjustment is described in Appendix B Spacing between Characters as a complete table, in accordance with the concept of character class in 3.9 About Character Classes. |
The positioning of characters and symbols may vary depending on the following.
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Is the character width full-width, half-width, or something else?
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Is it allowed or forbidden to place the character or symbol at the line head? If it is allowed, how will it be placed?
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Is it allowed or forbidden to place the character or symbol at the line end? If it is allowed, how will it be placed?
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Are characters and symbols appearing in sequence in solid setting, or will there be a fixed space between them? For example,
sequences of ideographic characters (cl-19) and hiragana (cl-15) are set solid, and for Western characters (cl-27) following hiragana (cl-15) there will be quarter em space.
-
Is it allowed to have a line break within a sequence of characters? For example, there must not be a line break in a sequence
of grouped numerals (cl-24).
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Is it allowed to use the space between characters in a sequence during line adjustment processing? For example, is inter-character
space reduction or addition possible between the characters appearing in sequence? Another issue to be decided is the preferred
order for adjustment processing, and the amount of the allowed adjustment.
During layout processing, the issues mentioned in the previous section are addressed by grouping characters and symbols according
to their characteristics, and handling them as character classes.
JIS X 4051 also provides similar character classes but that are slightly different from this document. Furthermore JIS X 4051 states that it is implementation-defined how to handle characters that are not explicitly mentioned, e.g. whether they should belong to either class or not.
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(note 1)
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In JIS X 4051 Annex 1, the member characters and symbols of each character class are specified as a mapping table to JIS X 0213 character names.
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A few character classes of this document are modified from JIS X 4051. In Appendix A Character Classes, there is a whole mapping table to ISO/IEC 10646 Annex A collection 285 (BASIC JAPANESE) and collection 286 (JAPANESE NON IDEOGRAPHIC EXTENSION). All character classes of this document are as follows:
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Opening brackets (cl-01)
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Example:
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‘“（〔［｛〈《「『【
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etc.
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Closing brackets (cl-02)
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Example:
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’”）〕］｝〉》」』】
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etc.
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(note 1)
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In JIS X 4051, IDEOGRAPHIC COMMA "、" and COMMA "," are classified as closing brackets (cl-02), because they have similar positioning methods. However, in this document, the handling of IDEOGRAPHIC COMMA "、" and COMMA ","
are described as an independent class, named commas (cl-07).
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Hyphens (cl-03)
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Dividing punctuation marks (cl-04)
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Middle dots (cl-05)
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Full stops (cl-06)
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Commas (cl-07)
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Inseparable characters (cl-08)
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Iteration marks (cl-09)
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(note 1)
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In JIS X 4051, iteration marks such as IDEOGRAPHIC ITERATION MARK "々" are classified as "no line break allowed before" characters. In this document, IDEOGRAPHIC ITERATION MARK "々" etc. are classified as iteration marks (cl-09).
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(note 2)
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There is another method where it is permitted to break a line before IDEOGRAPHIC ITERATION MARK "々". In this case, IDEOGRAPHIC ITERATION MARK "々" is regarded as a member of ideographic characters (cl-19).
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Prolonged sound marks (cl-10)
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(note 1)
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In JIS X 405, KATAKANA-HIRAGANA PROLONGED SOUND MARK "ー" is a member of "Japanese characters with no line break allowed before". In this document KATAKANA-HIRAGANA PROLONGED SOUND MARK "ー" is the only member of prolonged sound mark (cl-10).
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(note 2)
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In JIS X 4051, it is permitted to exclude KATAKANA-HIRAGANA PROLONGED SOUND MARK "ー" from the "Japanese characters with no line break allowed before" character class.
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(note 3)
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When it is permitted to break a line before KATAKANA-HIRAGANA PROLONGED SOUND MARK "ー", KATAKANA-HIRAGANA PROLONGED SOUND MARK "ー" is regarded as a member of the katakana (cl-16) class.
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Small kana (cl-11)
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Example:
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ぁぃぅぇぉァィゥェォっゃゅょッャュョ
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etc.
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(note 1)
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In JIS X 4051, small katakana letters, such as KATAKANA LETTER SMALL TU "ッ", are regarded as members of "Japanese characters with no line break allowed before" character class. In this document, small katakana letters are classified in small kana (cl-11). Accordingly, the "Japanese characters with no line break allowed before" character class in JIS X 4051 is divided to three separate classes; iteration marks (cl-09), prolonged sound mark (cl-10) and small kana (cl-11).
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(note 2)
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In JIS X 4051, it is permitted to exclude small kana letters (ぁぃぅァィゥ etc.) from the "Japanese characters with no line break allowed before" character class as an implementation definable option.
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(note 3)
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When it is permitted to break a line before small hiragana (ぁぃぅ etc.) are regarded as members of the hiragana (cl-15) class, and small katakana (ァィゥ etc.) are regarded as members of the katakana (cl-16) class.
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Prefixed abbreviations (cl-12)
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Postfixed abbreviations (cl-13)
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Full-width ideographic space (cl-14)
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Example:
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U+3000 IDEOGRAPHIC SPACE
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Hiragana (cl-15)
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(note 1)
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The reason kanji etc. (Japanese characters except 1. to 12.) and hiragana are regarded different classes in JIS X 4051, is the difference in the case of ruby, and specifically the handling in terms of characters jutting out of the base and overhanging adjacent characters.
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Katakana (cl-16)
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(note 1)
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In JIS X 4051, katakana and kanji are included in the same class (Japanese characters except for 1. to 12.). However, in this document, when ruby characters jut out of the base characters and overhang adjacent hiragana or katakana, the handling is same. That is the reason that in this document, katakana (cl-16) is an independent character class.
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Math symbols (cl-17)
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(note 1)
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In JIS X 4051, math symbols (＋－÷×etc.) and math operators (＝≠＜＞≦≧⊆⊇∪∩etc.) are included in the "Japanese characters excluded from 1. to 12." class or Western character class. However, handling of math symbols and math operators adjacent to Western character or Arabic numerals is different from kanji. So, in this document, new math operators (cl-18) and math symbols (cl-17) classes are defined.
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Math operators (cl-18)
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Ideographic characters (cl-19)
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Example:
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亜唖娃阿哀愛挨〃仝〆♂♀
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etc.
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Characters as reference marks (cl-20)
Characters which are inside verification seal (those are characters inside a verification seal that appear in the line just after the item applicable for reference marks of notes)
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Ornamented character complexes (cl-21)
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(note 1)
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The name of this class in JIS X 4051 is "Characters included in ornamented base characters complex". The meaning of "base characters complex" is characters in a complex including ruby, ornament characters and emphasis dots.
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Simple-ruby character complexes (cl-22)
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(note 1)
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The name of this class in JIS X 4051 is "Characters included in base characters complex with ruby (excluding jukugo-ruby)".
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Jukugo-ruby character complexes (cl-23)
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(note 1)
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The name of this class in JIS X 4051 is "Characters included in base characters complex with jukugo-ruby".
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Grouped numerals (cl-24)
Sequences of European numerals which are not full-width and are handled as Japanese text, the decimal point or the comma and space used as grade indicator in number.
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Unit symbols (cl-25)
Units described here include combinations of Latin script and Greek script characters used for international units (SI).
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(note 1)
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There are units created with combinations of Latin and Greek script characters with a full-width character frame (full-width units). Such units are not part of the characters for units described here. Furthermore, full-width characters for units are mainly used in vertical writing mode. Their usage in horizontal writing mode is regarded as bad style and should be avoided (see [Fig.182]).
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Western word space (cl-26)
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Western characters (cl-27)
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(note 1)
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Western characters (cl-27) include punctuation marks, such as commas, used in Western context. Among these punctuation marks, several marks are used both in a Japanese context and Western context. However, these marks have different character shapes depending on whether they are used in a Japanese context or Western context. For example, LEFT PARENTHESIS "(" and RIGHT PARENTHESIS ")" has not only different width (Japanese, half em, Western, proportional) but are also different in line position (Japanese, center of the character frame in the inline direction, Western, base line and descender line dependent) and design (Japanese, slightly bent and constant line thickness, Western, strongly curved and dynamic line thickness). The usage of these two differently designed commas should be explicit. Usually, in a Japanese context Japanese design is used, and in Western context Western design is used. However, there are some ambiguous cases, such as "エディター（editor）は……". In this case, English spelling is indicated using parentheses in a Japanese line of text. In this particular case, Japanese design is better.
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Warichu opening brackets (cl-28)
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Warichu closing brackets (cl-29)
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Characters in tate-chu-yoko (cl-30)
For each character class it is possible to describe whether the characters may appear at the line head or line end or not,
the positioning method for the line head or line end positions (if available), the amount of space between sequences of several
characters, and the combination with character classes before or after the characters (in a 2 dimensional table). In JIS X
4051 this is shown in table 5 "Amount of space (between characters)".
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(note 1)
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For the presentation as a two dimensional table, it becomes necessary for each class to have separate items about "line head"
(the column about the character classes appearing before) and "line end" (the column about the character classes appearing
after). If it is forbidden that the characters of the class appear at the line head or line end, JIS X 4051 uses an "X" mark
in the columns for "line head" and "line end".
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Also, it can be defined for each combination of the character classes (in a two dimensional table) whether the characters
of classes appearing in sequence allow for a line break between them, or whether it is possible during line
adjustment processing to add inter character space between them. In JIS X 4051 these items are also shown in a two dimensional table. Table
6 shows whether a line break is possible, and table 7 shows if it is possible to add inter character space.
|
(note 1)
|
It is also possible to define for each combination of character classes whether it is possible to apply kerning during line
adjustment processing for character classes appearing in sequence. However, JIS X 4051 does not provide this information as
a two dimensional table, but only as a textual description.
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The width, in principle, of the space between each character or symbol in character classes used in this document is described in the table of Appendix B Spacing between Characters.
The combinations of adjacent characters and symbols in character classes used in this document, and where text is breakable or not, is described in the table of Appendix C Possibilities for Line-breaking between Characters.
The width of spaces between each character or symbol in character classes used in this document, and which can be reduced, is described in the table of Appendix D Opportunities for Inter-character Space Reduction during Line Adjustment. Also, expandable spaces are described in the table of Appendix E Opportunities for Inter-character Space Expansion during Line Adjustment.
