Mongolian Layout Requirements

Abstract

This document describes requirements for the layout and presentation of text in languages that use the Mongolian script when they are used by Web standards and technologies, such as HTML, CSS, Mobile Web, Digital Publications, and Unicode.

Status of This Document

This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at https://www.w3.org/TR/.

This document describes the basic requirements for Mongolian script layout and text support on the Web and in eBooks. These requirements provide information for Web technologies such as CSS, HTML and digital publications about how to support users of Mongolian script languages. Currently the document focuses on the Traditional Mongolian script as used for Mongolian. The information here is developed in conjunction with a document that summarises gaps in support on the Web for Mongolian.

The editor's draft of this document is being developed by the Mongolian Layout Task Force, part of the W3C Internationalization Interest Group. It is published by the Internationalization Working Group. The end target for this document is a Working Group Note.

To make it easier to track comments, please raise separate issues or emails for each comment, and point to the section you are commenting on using a URL.

This document was published by the Internationalization Working Group as a First Public Working Draft.

GitHub Issues are preferred for discussion of this specification.

Publication as a First Public Working Draft does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.

This document was produced by a group operating under the W3C Patent Policy. The group does not expect this document to become a W3C Recommendation. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.

This document is governed by the 1 March 2019 W3C Process Document.

1. Introduction

1.1 About this document

This standard describes the Mongolian format standard, which can be used and achieve implementation in the CSS, SVG and XSL-FO, and it can also be used as the reference documents for office software. It mainly focuses on the Mongolian script and its features, the basic module of Mongolian text, page layout, new CSS standard and accessories.

1.1.1 Scope

The document describes the rules of composition of various types of text written in traditional Mongolian script and pictures, etc. in various network formats. The purpose of this standard is not to provide complete solution, but to describe the important basic information needed in the implementation in a computer.

The main purpose of this document is to provide standardization and guiding rules for the display and application of traditional Mongolian script in the web. However, the more complex layout requirements such as paper layout are not included in this document. Thus, this document includes the most basic rules of display of page and characters of the traditional Mongolian script, aiming at formulating the corresponding standards of web display and application of Mongolian script for the web application vendors to follow this standard of display and application of Mongolian script in the web.

1.1.2 Terminology

The following terms and definitions apply to this standard.

Composition: The composition in the W3C Standard Format includes Mongolian characters, punctuation marks, and other marks related to the script.
Mongolian Space: Two spaces are used in Mongolian, U+0020 SPACE and the Mongolian space U+202F NARROW NO-BREAK SPACE.
Mongolian Symbols: This refers to various symbols used in Mongolian text. In formulating the Mongolian coding standard, some of the codes is used in the coding area of the Mongolian standard, while the rest are symbols used in the scripts of other ethnic groups, due to the fact that some symbols are borrowed from other ethnic groups.
Baseline: Baseline in Mongolian is called “Nirogo”. Mongolian writing is generally aligned to the baseline.
Writing Direction: It refers to the default direction of writing. For example, English writing direction is horizontal from top to bottom, while the Mongolian writing is vertical from left to right.
Text Width: Text width indicates the distance from the word at the left start to the word at the right ead in a line in Mongolian, in the equivalent of the height of the horizontal English or Chinese text writing.
Text Height: Text height refers to the height of a Mongolian word, in equivalent of the width of the horizontal English or Chinese text writing.
Text Spacing: Text spacing refers to the gap between the Mongolian words.
Leftline and Rightline: As the Mongolian writing is vertical, the right line, the left line and the line through is equivalent to the underline and overline in the horizontal English or Chinese text writing.

1.2 Gap analysis

This document is pointed to by a separate document, Mongolian Gap Analysis, which describes gaps in support for Mongolian on the Web, and prioritises and describes the impact of those gaps on the user.

Wherever an unsupported feature is indentified through the gap analysis process, the requirements for that feature need to be documented. This document is where those requirements are described.

This document should contain no reference to a particular technology. For example, it should not say "CSS does/doesn't do such and such", and it should not describe how a technology, such as CSS, should implement the requirements. It is technology agnostic, so that it will be evergreen, and it simply describes how the script works. The gap analysis document is the appropriate place for all kinds of technology-specific information.

Initial content for this document drew on Chinese standards work. (EXPAND)

The document International text layout and typography index (known informally as the text layout index) points to this document and others, and provides a central location for developers and implementers to find information related to various scripts.

The W3C also maintains a tracking system that has links to github issues in W3C repositories. There are separate links for (a) requests from developers to the user community for information about how scripts/languages work, (b) issues raised against a spec, and (c) browser bugs. For example, you can find out what information developers are currently seeking, and the resulting list can also be filtered by script.

3. Characters and phrases

3.1 Punctuation

3.1.1 Punctuation rules

There are some specific requirements while using the Mongolian punctuation:

Commas, periods, exclamation marks, question marks, or colons cannot be used at the beginning of a line.
Opening brackets cannot be used at the end of a line.
Closing brackets cannot be used at the beginning of a line.
The colon and "《" of the opening bracket cannot be used separately, which means they must be used together and they are not allowed to be used at the beginning of a line.
Dash consists of two long separators, which cannot be separated, i.e. one cannot be used at the beginning of a line and the other is at the end. However, it is allowed to appear at the beginning of the line when a paragraph begins.
Mongolian names of Mongolian punctuation and writing direction are as shown in Figure 1, namely the writing direction is the same as that in the graph. Need to clarify the meaning of this bullet.

Figure 1 Mongolian punctuation sample.
Mongolian punctuation should be centered vertically, as shown in Figure 2.

Figure 2 Alignment relationship between punctuation and Mongolian script text.

3.1.2 Display rules for Mongolian space

Mongolian word suffixes are separated from the preceding word using U+202F NARROW NO-BREAK SPACE, rather than U+0020 SPACE. For example, the code points that make up the suffix “ ᠤᠨ” are: 0x202F 0x1824 0x1828.

Figure 3 The difference between the common space and Mongolian space.

U+202F NARROW NO-BREAK SPACE and a following suffix cannot appear at the beginning of a line. For example, Figure 4 shows the correct approach and Figure 5 shows an incorrect approach.

3.2 Text boundaries & selection

3.2.1 Selection rules

Inline selected text must overlap the Mongolian baseline, as shown in Figure 6. Multi-line selection must follow the writing direction of the Mongolian script, i.e., text direction from top to bottom and from left to right, as shown in Figure 7.

Figure 6 The effect of choosing a single-line text.

Figure 7 The effect of choosing multi-line text.

3.2.2 Cursor movement rules

Striking cursor movement keys on the keyboard, including “←”, “→”, “↑”, “↓”, “Page Up”, “Page Down”, “Home” and “End”, should produce movement that follows the writing direction of the Mongolian script from top to bottom and from left to right. For example, the cursor moves to the left after striking the “←” key; the cursor moves to the right when striking the “→” key. The cursor moves down after striking the “↓” key. When the cursor reaches the bottom of the current line, and the key “↓” is pressed again, the cursor will move right and to the top of the next line, as shown in Figure 8. In the case of the “↑” key, the opposite occurs.

Figure 8 Illustration of cursor movement.

3.2.3 Mouse pointer rules

The mouse pointer in text editing is shown in Figure 9.

Figure 9 Illustration of the text cursor in Mongolian text.

The scrollbar will scroll left and right when mouse wheel is scrolling, that is, the scrollbar will move left or the text will move right when mouse wheel is scrolling forward; the scrollbar will move right or the text will move left when mouse wheel is scrolling backward.

The cursor shape during text editing (shown in Figure 9) must be aligned at the base on the midpoint of the Mongolian script baseline, that is, the midpoint of the Mongolian script baseline overlaps the midpoint of the cursor, with the length no longer than the middle line between the two lines of the text, as shown in Figure 10.

Figure 10 Illustration of cursor movement.

3.3 Text decoration

The “right line” in Mongolian writing is to the right of the text, and is used similarly to the underline of horizontal English and Chinese text. The “left line” is to the left of the text, and is used similarly to the overline of horizontal English and Chinese text. The strikethrough is a baseline-centered vertical line as shown in Figure 11.

Figure 11 Illustration of the right line, the left line and the strikethrough.

Underline, overline and strikethrough in mixed composition with other languages are shown in Figure 12:

Figure 12 Underline, overline and strikethrough as mixed with other languages.

Lines alongside the text may break on the spaces between words. When doing so, the gaps introduced before suffixes by U+202F NARROW NO-BREAK SPACE and U+180E MONGOLIAN VOWEL SEPARATOR should not be skipped. Even though there is a gap, suffixes are considered part of the word. See an example in the second word of Figure 13:

Figure 13 When inter-word spaces are skipped, gaps produced by NNBSP or MVS are not.

3.4 Other inline features

3.4.1 Mongolian text width, height and spacing

Due to the different height of Mongolian text, in order to ensure that every character is in fully displayed and the whole word looks beautiful, the height of each letter must keep in balance. The spaces between words must be different from the common gaps before suffixes, whose code point is U+202F NARROW NO-BREAK SPACE. See Figure 14:

Figure 14 The height, width and spacing of Mongolian words.

4. Lines and Paragraphs

4.1 Line breaking

Line-breaking should not split words. Figure 15 shows correct line-breaking, without breaking the Mongolian words. Figure 16 shows incorrect line-breaking for “” and “”.

4.2 Text alignment

Text alignment includes "left alignment", "horizontal centering", and “right alignment ”, as well as “top alignment”, “vertical centering”, “bottom alignment”and “top-bottom alignment”.

"Left alignment ", "horizontal centering" and “right alignment” are the alignment rules that apply inside a line. “Top alignment”, “horizontal centering”, “bottom alignment” and “top-bottom alignment” are the alignment rules in a page or a paragraph of a multi-line text.

Among "left alignment", "horizontal centering" and “right alignment”, “horizontal centering” is a default option which means that the Mongolian text will align based on its baseline axis. “Left alignment” means that the text will move left a certain distance, which shows obvious differences compared with the text after setting “horizontal center”. “Right alignment” means that the text will move right a certain distance after, which shows obvious differences compared with the text after setting “horizontal center”.

Among “Top alignment”, “vertical center”, “bottom alignment” and “top-bottom alignment”, “top-bottom alignment” is a default option which means that the words in the upper and the lower boundary of a multi-line text in a paragraph or a page are all aligned. Its alignment method is that spaces in the text are stretched in the same proportion. “Top alignment” means that the words in the upper boundary of a multi-line text in a paragraph or a page are all aligned without considering the alignment of the lower boundary and stretching the space between words. “Vertical center” means the words in the upper and the lower boundary of a multi-line text in a paragraph or a page do not need to align and leave the same blank under the condition of no-stretching space between words.

4.3 Counters, lists, etc

The display of these controls needs to pay attention to the direction of the output. That is to say, the primary display of the number 1, 2, 3, etc. is from left to right. The effect of the following code is as shown in Figure 17. Note how the text is centered on the vertical midline. The separator dots for the numbering are not centre-aligned. We should probably mention that. Also, shouldn't the numbers be rotated counter-clockwise?

4.4 Baselines

Mongolian is aligned to a baseline that runs down the center of the writing, and all text is aligned to this baseline as shown in Figure 18:

Figure 18 The aligning baseline for Mongolian.

4.4.1 Mixed Arrangement Rules with Other Languages

When mixed with other languages, the text in those languages should also be centre-aligned along the Mongolian baseline.

4.4.2 Mixed Arrangement Rules with Numbers and Latin

There is no obvious midcourt line in numbers and Latin. Therefore generally, half of the text height is regarded as a midcourt line position. When Mongolian script is mixed with numbers and Latin, the line of half of the text height should be aligned with Mongolian midcourt line. When font size of numbers is the same as Mongolian’s, it will be slightly larger, so some handling methods should be taken to avoid the problem, such as the methods listed in Figure 19.

Figure 19 The mixed arrangement of Mongolian, Latin and numbers.

4.4.3 Mixed Arrangement Rules with Chinese and Japanese

For mixed arrangements with Chinese or Japanese, note the following:

Chinese and Japanese cannot be displayed in on their side. They must be displayed upright, as in horizontal Chinese or Japanese.
The center line of Chinese or Japanese text (the width in this case) needs to be aligned with the centre baseline of the Mongolian text.
Pay attention to the top alignment and bottom alignment of the Mongolian text. In the same line, the mixed display of Mongolian and Chinese needs attention to produce a balanced alignment. When displayed, it should stretch space, but empty distance or space should not be added in Chinese text. Does this mean that no inter-character spacing should be applied to the Chinese?
Mongolian is smaller than Chinese or Japanese in the same font size, so some handling methods should be taken to avoid the problem, such as methods listed in Figure 20.

Figure 20 The mixed arrangement of Mongolian and Chinese.

5. Layout & pages

5.1 General page layout & progression

5.1.1 Bookbinding and the Direction of Page Turning

In general, bookbinding is on the left side, as shown in Figure 21:

The direction of page turning is to the left, as shown in Figure 22:

Figure 22 The direction of page turning.

5.1.2 Paper direction

Generally, landscape is the default Mongolian format, as shown in Figure 23.

Figure 23 Example of landscape paper direction.

5.1.3 Paper scrolling direction

By default, pages should scroll from left to right, as shown in Figure 24.

Figure 24 The direction of page scrolling.

5.1.4 The scrolling direction of scroll bars

When the amount of text exceeds the prescribed space available, a scroll bar needs to be displayed. The default display position of the scroll bar is along the bottom of the corresponding space. (The simultaneous display of both horizontal and vertical scroll bars has not been installed).

Figure 25 Position and scrolling direction of scroll bar.

5.1.5 Columns

Columns in Mongolian text should be divided vertically.

5.2 Vertical text

The Mongolian writing direction is shown in Figure 27.

5.3 Tables

When setting writing-mode:tb-lr using CSS (grammar will have a little difference according to various browsers), the table will support vertical display feature of Mongolian script. When setting default options for the text in a table, it will display horizontally centered, that is, the upper and the lower center lines of the table cell will align at the center line of the baseline of the Mongolian text, as shown in Figure 28.

Figure 28 The aligning baseline for Mongolian.

5.4 Page numbering, running headers, etc

In the Mongolian format, page numbers should be displayed on the upper or lower side of the page.

Figure 29 Adding the horizontal type and number on the page number .

5.5 User interaction

All input controls need to be adjusted to match the characteristics of the vertically typeset Mongolian text. For example, controls like text fields and buttons need to support to input and display of text vertically, and furthermore the cursors in text and passwords need to conform to the cursor style as shown in Figure 9.

Figure 30 The display of input controls and the alignment of Mongolian script.

5.5.1 Select

The select box appearing in the following HTML code should be displayed as shown in Figure 31. According to the default setting, the scroll bar is at the bottom and starts at the left. To see the contents at the end of the list, it scrolls from left to right. The scrolling of the mouse wheel should be in accordance with illustration in Figure 32. While selecting a column, the selected text and the selected background color should conform to the principle of aligning to the Mongolian vertically-centered baseline (see the descriptions in Figure 30).

Figure 32 Mongolian standard select box.

5.5.2 Textarea

Textarea is an important control, and is required in the text input, edit, and display. Scrollbar movement accords with requirements of the select control in § 5.5.1 Select. The display and moving direction of the cursor should be consistent with the standard for cursor movement in § 3.2.2 Cursor movement rules. In some browsers, there are functions for stretching the size of the textarea. The stretching icon should be in the lower right corner, and the textarea scaling accords with the mouse dragging. The rows and cols attribute of textarea are the opposite of those in horizontal text. Its specific attributes are as the following: rows {int} : showing the column number and cols {int} : showing the row number.

Figure 33 Display status of the standard textarea.

5.5.3 Label

The label control mainly considers text midcourt line aligning principles. ( See the descriptions in § 4.4 Baselines). The label display for the following code is shown in Figure 34.

Figure 34 The display of label controls.

5.5.4 Fieldset

As shown in Figure 35, which is an example fieldset generation with the following code, the components are aligned along the centred-vertical Mongolian baseline.

5.6 More page layout & pagination

5.6.1 Mixed arrangement of text and illustrations (or other non-text objects)

The illustrations here include ordinary picture formats, textboxes, charts, media objects and so on, all of which are called illustrations in what follows. There are many ways (as shown in Figure 36) of mixing the arrangements of text and illustrations but, no matter which way is used, some principles need to be obeyed.

The illustration cannot be rotated, that is, the original illustration is inserted just as it is. The illustration cannot be rotated into the vertical one just because of vertical text.
The Mongolian script around the inserted illustrations cannot be broken inside the word. The rules of the beginning and end of lines are the same as the original ones.

Figure 36 Mixed arrangement of text and illustrations (or other non-text objects).

A. Suggestions about Formulating New CSS Standard

When Mongolian webpage is created, the page direction should be designated: CSS-MONGOLIAN-LAYOUT:Y. Designating the option means that all page elements should be arranged in accordance with the requirement of vertical column script. Meanwhile, there are the main requirements: script should conform to the habit of Mongolian writing -----arrangement from top to bottom and from left to right (see the descriptions in 2.2.3); textboxes, buttons and list order are all displayed in vertical column; pictures, videos and the other third party controls do not need to accord with the requirement of vertical column.
In mixed arrangement with other languages, Mongolian text is X larger than the other texts. Designating the option requires that the size of Mongolian in all control texts should be automatically X larger than the size of the text of other scripts or X smaller under the condition of using minus.
When arranged with other languages, Mongolian should follow the midcourt line aligning principles as the following. when the option CSS-MONGOLIAN-MOVE- WAIST:X px is designated, Mongolian text in all control texts should move X px to left or right so that it can be aligned with the midcourt line of other texts. Because the midcourt line cannot be aligned well under the condition, the option needs to be set.
When arranged with other languages, Mongolian font should be set as CSS-MONGOLIAN-FONT:MongolianFontName. When the option is designated, Mongolian font in all control texts should be changed into MongolianFontName, while other languages’ font should accord with default font in the system. Because the change of Mongolian font will affect Chinese font when it is arranged with Chinese or other languages and sometimes, Chinese will be displayed in the way of lying down.
Whether Mongolian space (0x202F) is stretched: CSS-MONGOLIAN-SPACE:Stretch|Normal, when the Stretch option is designated, the length of Mogolian space should be stretched as that of normal space. While the option Normal is designated, Mongolian space should not be stretched, and should be displayed in the length of the font library.
Whether the Mongolian vowel space mark MVS (0x180E): is displayed: CSS-MONGOLIAN-MVS:Display|Normal, when the option Display is designated, there will be a small hollow rectangular on the screen with the size in the font library, but the rectangular will not be shown when it is printed. When the option Normal is designated, there will be no picture on the screen, but it will occupy a space of the size in the font library.