Usefulness of ::first-letter in non-Latin scripts

Background

The latest working draft of CSS3 Selectors proposes the ::first-letter pseudo-element.

See http://www.w3.org/TR/2005/WD-css3-selectors-20051215/#first-letter

The ::first-letter pseudo-element represents the first letter of the first line of a block, if it is not preceded by any other content (such as images or inline tables) on its line.

It allows that first letter to be styled individually, without markup. It may be used for "initial caps" and "drop caps", which are common typographical effects in text in Latin script.

We commented to the CSS Working Group that they need to define 'letter' more carefully, and proposed that they specify that 'letter' equates to 'default grapheme cluster', as described in the Unicode Standard Annex #29.

See http://www.unicode.org/reports/tr29/#Grapheme_Cluster_Boundaries

(A rough and ready explanation of this is that base characters and any following combining characters are styled together. So

0065: e LATIN SMALL LETTER E + 0301: ́ COMBINING ACUTE ACCENT

would be handled as a single letter.)

We also suggested that implementors should then be encouraged to provide tailored algorithms on a per language basis to cope with anomolies, particularly such as may occur in non-Latin scripts.

Here are some initial questions:

[1] Are there scripts that would never use this approach?

[2] We mention 'initial caps' and 'drop caps' above. What other types of styling would be commonly applied in other scripts if this feature were available?

[3] What script features would cause difficulties, eg syllabic groupings (see the example of indic script example below), ligatures, cursive text (eg. Arabic, Urdu, etc.), and how would the script normally deal with them?

Please send your comments to www-international @ w3.org Archive: http://lists.w3.org/Archives/Public/www-international/

What follows are some examples of questions that spring to mind.

SYLLABIC INDIC SCRIPTS

In the Hindi word स्थिति ('sthiti') the sequence of characters in the first syllable is as follows in memory:

0938: स DEVANAGARI LETTER SA 094D: ् DEVANAGARI SIGN VIRAMA 0925: थ DEVANAGARI LETTER THA 093F: ि DEVANAGARI VOWEL SIGN I

The displayed text, however, is

The first syllable of the word 'sthiti' in Hindi, showing the positions of the characters after display.

Note how the vowel sign appears to the left of the first character, not the third.

The default grapheme clusters here are, I believe, 0938+094D, then each of the following two characters.

Would Devanagari-based languages use special styling for initial syllables? If so, would they actually apply the styling to the vowel sign alone, or to the whole syllable?

LIGATURES

If a script styles the 'first letter', but that letter is part of a ligature (ie. a single glyph representing more than one underlying character), would it be ok to split the ligature, or should the other characters that compose the ligature also be styled?

CURSIVE SCRIPTS

Since Arabic and Mongolian letters in a word are normally joined, has first letter styling been used at all in these scripts?

CHINESE, JAPANESE, KOREAN

Do languages using these scripts do first letter styling?

RUSSIAN, GREEK, ARMENIAN, etc.

Is first letter styling common practise in these scripts too?