Gap analysis checklist
Arabic & Persian (Arabic script) for HTML/CSS
(Draft)
The W3C needs to make sure that the text layout and typographic needs of scripts and languages around the world are built in to technologies such as HTML, CSS, SVG, etc. so that Web pages and eBooks can look and behave as people expect around the world.
This page is a checklist of items to consider when investigating the level of support that is provided for a given script or language. If you want to raise an issue or comment against this page, use the github issues list.
Each section starts with a prompt in italicised text, intended to help you think of things that might be addressed in that section. When summarising the situation, try to indicate which languages you are covering with your text. Use separate subheadings where there are divergent issues related to specific languages.
For each section element with a topic class, add one of the following classes to that section tag. Then add any useful comments in the following section element with the details class.
- ok (no problems)
- na (not applicable)
- advanced (work needed to support advanced applications, such as fine quality book production)
- basic (work needed to support basic styling for basic web page use)
- broken (work needed to enable interoperable semantics, or basic display on the Web).
Characters & phrases
Encoding considerations
Are there any character repertoire issues preventing use of this script on the Web? Do variation selectors need attention?
Font styles
Do the standard fallback fonts used in browsers match expectations? Are special font features needed for this script that are not available? Do italic fonts lean in the right direction? See available information or check for currently needed data.
It would be useful to be able to control the direction in which 'italicised' or 'oblique' text slants, since it may need to slant to the left.
Glyph control
Does this script require additional work to support altering the position or shape of glyphs, for example adjusting the distance between the base text and diacritics, or changing the glyphs used in a systematic way? See available information or check for currently needed data.
It would be useful to be able to control the height of diacritics relative to the base consonant for advanced typographic control.
Cursive text
If this script is cursive (eg. Arabic, N'Ko, Syriac, etc), are there problems or needed features related to the handling of cursive text? See available information or check for currently needed data.
Various changes in styling currently break cursive connections. This should not happen. (Add details)
Text boundaries and selection
When you double- or triple-click on the text, is the expected range of characters highlighted? When you move through the text with the cursor, or backspace, etc. do you see the expected behaviour? Are there issues when applying punctuation than could be fixed by the application? See available information or check for currently needed data.
Quotations
Are there any issues when dealing with quotations marks, especially when nested? Should block quotes be indented or handled specially? See available information or check for currently needed data.
In HTML and CSS the styling applied to nested multilingual quotations when using the q element chooses quotation marks based on the language of the text inside the quotation, rather than outside.
Numbers and digits
If the script has its own set of number digits, are there any issues in how they are used? Does the script or language use special format patterns that are problematic? See available information or check for currently needed data.
Not yet clear whether there are issues related to the handling of arabic and eastern arabic script digits.
Transforming characters
Does your script need special text transforms that are not supported? Does your script convert letters to uppercase, capitalised and lowercase alternatives according to your typographic needs? Do you need to to convert between half-width and full-width presentation forms? See available information or check for currently needed data.
Inter-character spacing
Many scripts create emphasis or other effects by spacing out the letters or syllables in a word. We know there are questions here about how this should work in Indic and SE Asian scripts, and in Arabic-based scripts. Are there requirements for other scripts that we should add? (For justification related spacing, see below.) See available information or check for currently needed data.
It is very common in Arabic script to stretch words or phrases to a particular width (eg. to match a Latin translation or transcription above or below). This is achieved by lengthening the connections between letters, and to some extent by use of wide glyph variants, etc. The rules for which part of the text to stretch and how far are complicated - this is not the even spacing that usually occurs in tracked Latin text. There are currently no mechanisms for managing this process effectively in HTML/CSS.
Ruby annotation
The ruby spec currently specifies an initial subset of requirements for fine-tuning the typography of phonetic and semantic annotations of East Asian text, including furigana, pinyin and zhuyin fuhao systems. Is is adequate for what it sets out to do? What other controls will be needed in the future? See available information or check for currently needed data.
Text decoration
Some aspects related to the drawing of lines alongside or through text involve local typographic considerations. Do underlines need to be broken in special ways for this script? Do you need support for additional line shapes or widths? Does the distance or position of the lines relative to the text need to vary in ways that are not achievable? Are lines correctly drawn relative to vertical text? See available information or check for currently needed data.
It must be possible to position under- and overlines further away from the baseline than for Latin text. There is not currently a way to achieve effective underlining in a way that works with the Arabic script.
Emphasis & highlights
Bold and italic are not always appropriate for expressing emphasis, and some scripts have their own unique ways of doing it, that are not in the Western tradition at all. Does this script require support for emphasising or highlighting text that cannot be achieved currently? See available information or check for currently needed data.
Inline notes, etc.
Does your script have special ways of representing inline notes (such as wakiten or kumimoji in Japanese) or other inline features that need to be supported? See available information or check for currently needed data.
Bidirectional text
If this script runs right-to-left, are there any issues when handling that? Is bidirectional text adequately supported? See available information or check for currently needed data.
Edge still doesn't support directional isolation.
There are questions about how to transmit information about the expected directional behaviour of certain strings.
RLI, LRI, etc are still not well supported.
....
Lines & paragraphs
Line breaking
Does the browser capture the rules about the way text in your script wraps when it hits the end of a line? What characters should not appear at the end or start of a line, and what should be done to prevent that? Does line-breaking wrap whole 'words' at a time, or characters, or something else (such as syllables in Tibetan)? See available information or check for currently needed data.
Hyphenation
Is hyphenation used for your script, or something else? If hyphenation is used, does it work as expected? See available information or check for currently needed data.
No hyphenation is used for Arabic when used with Arabic and Persian languages.
Justification & line-end alignment
When text in a paragraph needs to have flush lines down both sides, does it follow the rules for your script? Does the script need assistance to conform to a grid pattern? Does your script allow punctuation to hang outside the text box at the start or end of a line? Where adjustments are need to make a line flush, how is that done? Do you shrink/stretch space between words and/or letters? Are word baselines stretched, as in Arabic? See available information or check for currently needed data.
Arabic script text uses various strategies for justification, which are different from say Latin script text. CSS doesn't provide any way to manage most of these behaviours. [Not sure whether to mark this a basic or advanced issue.]
Counters, lists, etc
The CSS Counter Styles specification describes a limited set of simple and complex styles for counters to be used in list numbering, chapter heading numbering, etc. Are the details correct? We have another document that provides over 120 templates for user-defined counter styles in over 30 scripts. Are there more? Are there other aspects related to counters and lists that need to be addressed? See available information or check for currently needed data.
Arabic script text uses local counter styles. While some of these are supported by some browsers, the set of symbols used and their order varies by language. Custom counter styles can be created using Firefox only. The CSS spec needs to become a Rec and more browsers need to support it.
Initial letter styling
Does the browser or ereader correctly handle special styling of the initial letter of a line or paragraph, such as for drop caps or similar?
See available information or check for currently needed data.
The parameters for managing initial-letter styling for the Arabic script are not well understood by the technology (for example, how to manage cursiveness across the boundary).
Baselines & inline alignment
Does the browser support requirements for baseline alignment between mixed scripts and in general? See available information or check for currently needed data.
White space and wrapping in source code
Do the rules for transforming white space in the source text for display meet the requirements of your script? This is particularly relevant for Far Eastern and South East Asian scripts, that don't use spaces between words.
Other paragraph features
In your script, is the first line of text typically indented at the start of a paragraph? Are there other features of paragraph design that are peculiar to your script? See available information or check for currently needed data.
Layout & pages
Bidirectional layout
When content can flow vertically and to the left or right, how do you specify the location of objects, text, etc. relative to the flow? For example, keywords 'left' and 'right' are likely to need to be reversed for pages written in English and page written in Arabic. See available information or check for currently needed data.
There needs to be wider adoption of logical keywords such as start and end, rather than left and right.
Vertical text
Are the script requirements for vertically oriented text met? What about if you mix vertical text with scripts that are normally only horizontal? Do you need a switch to use different characters in vertical vs. horizontal text? Does the browser support short runs of horizontal text in vertical lines (tate-chu-yoko in Japanese) as expected? Is the orientation of characters and the directional ordering of characters supported as needed? See available information.
Notes, footnotes, etc
Does your script have special requirements for notes, footnotes, endnotes or other necessary annotations of this kind in the way needed for your culture? See available information or check for currently needed data.
Page numbering, running headers, etc
Are there special conventions for page numbering, or the way that running headers and the like are handled? See available information or check for currently needed data.
?
More page layout and pagination
Some cultures define page areas and page progression direction very differently from those in the West (eg. kihon hanmen in Japanese). Is this an issue for you? Are widows and orphans relevant? In what order do pages progress, RTL or LTR? See available information or check for currently needed data.
Same as for English??
Other
Culture-specific features
Sometimes a script or language does things that are not common outside of it sphere of influence. This is a loose bag of additional items that weren't previously mentioned.
This section may also be relevant for observations related to locale formats (such as number, date, currency, format support).
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What else?
There are many other CSS modules which may need review for script-specific requirements, not to mention the SVG, HTML, Speech, MathML and other specifications.
What else is likely to cause problems for worldwide deployment of the Web, and what requirements need to be addressed to make the Web function well locally?
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If you have comments about this page, send them to ishida@w3.org.
Content last changed 2017-08-30 20:31 GMT
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