Writing systems

This page gives basic information on support for various aspects of writing systems: languages written in multiple scripts; writing direction; font rendering and input.

Multiple scripts, multiple dialects
Many languages are written with multiple scripts. Often this is possible but lacks support in the software, and sometimes it is difficult if not impossible to implement. Some languages do have a LanguageConverter that adds support for multiple writing systems.

Some languages have very similar dialects that are written in the same script(s) and can&mdash;on a technical level—be treated in the same way as different scripts.

LanguageConverter
For documentation on how to use LanguageConverter, see Writing systems/Syntax

LanguageConverter (LC) is a system based on language variants that automatically converts the content of a page into a different variant. A variant is mostly the same language in a different script. To use the LanguageConverter, go to your Internationalisation preferences. If you are on a wiki that supports conversion, you'll see an extra option for choosing the script.

T21044 -- this needs more documentation!

It is implemented for the following languages (as of March 2017; see languagesWithVariants for the latest list): And it is needed for many more languages!
 * Crimean Tatar (crh): Latin (crh-latn), Cyrillic (not latin)
 * English(en): Normal (en), Pig Latin (en-x-piglatin) (for testing, only when $wgUsePigLatinVariant is enabled)
 * Gan (gan): Simplified (gan-hans), Traditional (gan-hant)
 * Inuktitut (iu): Latin (ike-latn), Syllabics (ike-cans) [since 1.18]
 * Kazakh (kk): Cyrillic (kk-cyrl), Latin (kk-latn), Arabic (kk-arab)
 * Kurdish (ku): Latin (ku-latn), Arabic (ku-arab) [since ]
 * Tachelhit (shi): Tifinagh (shi-tfng), Latin (shi-latn) [since 1.19]
 * Serbian (sr): Cyrillic (sr-ec), Latin (sr-el)
 * Tajik (tg): Cyrillic (tg-cyrl), Latin (tg-latn)
 * Uzbek (uz): Cyrillic (uz-cyrl), Latin (uz-latin) [since 1.20]
 * Chinese (zh):
 * Simplified Script (zh-hans): China (zh-cn), Singapore (zh-sg), Malaysia (zh-my)
 * Traditional Script (zh-hant): Taiwan (zh-tw), Hong Kong (zh-hk), Macau (zh-mo)

Language code tags for scripts should follow the ISO 15924 standard.

A current limitation of this system is that it may be particularly bad at dealing with multiple writing systems based on the same underlying script. Chinese Wikipedians occasionally use  (unidirectional) for failing cases. As LC always tries to eat up the largest chunks of words using  in PHP,   (breaking up words) can be often useful too.

Supporting configuration
The WPULS/WPUVS functions in zhwp's sitelib allows for easy variant selection in userscript UIs. This can help script writers produce a variant-aware interface for users.

The PreviewWithVariant gadget allows Wikipedians to check conversion results in the editor preview. You can configure it for your own wiki.

"Foreign language marker" templates like should add "disable conversion" markers   around the quoted foreign text to avoid mis-conversion. On Hans/Hant wikipedias this becomes a concern for Japanese Kanji and Vietnamese Han Nom, while on wikipedias with Latin text marked for conversion this concern should be immediate.

The WikitextLC module allows for easily inserting LC commands to Lua output. Module:地区用词 allows for an adaptive output of the form "foo, known in PLACE and PLACE as bar, and PLACE as baz".

Directionality
Most writing systems operate as characters written left-to-right (LTR), with lines stacked from top-to-bottom (TtB).

A few common scripts (Arabic and Hebrew in particular) write characters right-to-left (RTL) -- see directionality support for more details on how we handle right-to-left and mixed bidirectional text with HTML output and CSS styles.

Note that an individual language can be used with scripts that have different directionalities, such as Kazakh and Kurdish which support Latin and Arabic variants.

Note also that the World Wide Web Consortium is working on developing more directionalities for the use in web pages, such as North East Asian top-to-bottom ones, with lines stacked either from left to right or right to left. 

Font rendering and input
Many scripts do not have proper fonts easily available to users. This may be because operating systems do not ship these fonts, or users don't know how to install them or don't have enough permissions to do this. The WebFonts extension tries to solve this by embedding the fonts in the wiki itself. Fonts will be served from the server and the user's system would not need to have the fonts installed.

Similarly, the Narayam extension adds support to be able to type a certain script, so users do not have to rely on external tools or support on their systems.