This document describes or points to requirements for the layout and presentation of Uighur text when it is used by Web standards and technologies, such as HTML, CSS, Mobile Web, Digital Publications, and Unicode.

This document describes the basic requirements for Uighur 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 Arabic scripts.

The editor's draft of this document is being developed as part of the Arabic script enablement initiative, 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 a separate issue for each comment, and at the start of the issue add a URL pointing to the section you are commenting on.

Some links on this page point to repositories or pages to which information will be added over time. Initially, the link may produce no results, but as issues, tests, etc. are created they will show up.

Introduction

The aim of this document is to describe the basic requirements for Uighur layout and text support on the Web and in eBooks. These requirements provide information for Web technologies such as CSS, HTML and digital publications, and for application developers, about how to support users of Uighur.

Contributors

The initial information in this document was created by Richard Ishida (W3C).

See also the GitHub contributors list for the Arabic Script Enablement project, and the discussions.

About this document

The aim of this document is to describe the basic requirements for Uighur layout and text support on the Web and in eBooks. These requirements provide information for Web technologies such as CSS, HTML and digital publications, and for application developers, about how to support users of Uighur.

The document focuses on typographic layout issues. For a deeper understanding of the Uighur orthography and how it works see Uighur Orthography Notes, which includes topics such as: Phonology, Vowels, Consonants, Encoding choices, and Numbers.

Gap analysis

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

Wherever an unsupported feature is identified 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.

Other related resources

To complement any content authored specifically for this document, the sections in the document also point to related, external information, tests, GitHub discussions, etc.

The Language enablement 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 has a repository with discussion threads related to the Arabic script, including requests from developers to the user community for information about how scripts/languages work, and a notification system that tracks issues in W3C working groups related to Arabic scripts. See a list of unresolved questions for Arabic script experts. Each section below points to related discussions. See also the repository home page.

All topics

Text direction

Bidirectional text

Arabic script is written from right to left. Numbers, even Arabic numbers, are written from left to right, as is text in a script that is normally left-to-right.

When the main script is Arabic, the layout and structure of pages and documents are also set from right to left.

Vertical text

Glyph shaping & positioning

Fonts & font styles

Context-based shaping & positioning

Cursive text

Arabic script is a cursive writing system; i.e, letters can join to their neighboring letters. Besides the core behavior of the script, there are some details on how content is encoded in Unicode, and some rules around joining behavior when rendering special cases.

Letterform slopes, weights, & italics

Typographic units

Characters & encoding

Grapheme/word segmentation & selection

Punctuation & inline features

Phrase & section boundaries

Quotations & citations

Emphasis & highlighting

Abbreviation, ellipsis & repetition

Inline notes & annotations

Other inline features

Data formats & numbers

Line & paragraph layout

Line breaking & hyphenation

Text alignment & justification

Text spacing

Baselines, line height, etc.

Arabic script ascenders and descenders extend much further than those of the Latin script, and care must be taken to correctly align text in the different scripts when they appear together.

Lists, counters, etc.

Styling initials