A dictionary describes languages, and in this article we describe OmegaWiki's notion of "language". OmegaWiki bases its notion on the ISO-639-3 standard, with some variation. There is a language table in the database.
 OmegaWiki's notion of language
OmegaWiki's list of language codes is generally drawn from the ISO 639-3 standard, which has some 7602 entries. This is a different list than the project codes used by MediaWiki. The ISO 639-3 standard is administered by the SIL, based on SIL's Ethnologue and the Linguist list.
 Scope of identifiers
SIL has this to say about the scope of language identifiers for individual languages:
- "There is no one definition of "language" that is agreed upon by all and appropriate for all purposes. As a result, there can be disagreement, even among speakers or linguistic experts, as to whether two varieties represent dialects of a single language or two distinct languages. For this part of ISO 639, judgments regarding when two varieties are considered to be the same or different languages are based on a number of factors, including linguistic similarity, intelligibility, a common literature, the views of speakers concerning the relationship between language and identity, and other factors."
The ISO 639-3 standard also contains codes for macrolanguages, that is:
- "...clusters of closely-related language varieties that, based on the criteria discussed above, can be considered distinct individual languages, yet in certain usage contexts a single language identity for all is needed."
The ISO 639-3 standard explicitly declines to encode dialects, where "...the term dialect is used as in the field of linguistics where it simply identifies any sub-variety of a language such as might be based on geographic region, age, gender, social class, time period, or the like." Thus it has one language code "eng" (English) which covers usage in the UK, USA, and some 104 other countries, including dozens of dialects from Cockney to Black English.
However, OmegaWiki finds it important to record distinctions between some local dialects. For example, it has separate language codes for "English", "English (United Kingdom)", and "English (United States)". Decisions to distinguish dialects in OmegaWiki by adding new language codes are made by the project leadership on a case-by-case basis.
 Future prospects
OmegaWiki intends to transition to ISO 639-6 as its list for linguistic entities. ISO 639-6's goal is to have codes for "comprehensive coverage of language variation". Presumably this would include codes for everything registered in ISO 639-3, and also dialects and scripts which are outside ISO 639-3's scope. ISO 639-6 is a draft as of June, 2007, and thus probably has months, maybe years of work before it becomes a final standard.
 Language, script, and orthography
ISO 639-3's scope for language identifiers includes aspects of spoken expression ("intelligibility") and written expression ("literature"). It covers both with a single language identifier. However, OmegaWiki's fundamental element of Expression is built of written, not spoken text. There are occasions where this distinction makes a difference.
The set of written marks, or graphemes, in which a language is written is known as a script. Multiple languages can be expressed using one script. For instance, the languages English and French are both written in the Latin script. However, some languages are written in multiple scripts. For instance, "azb" (South Azerbaijani) is written in Arabo-Persian script, Roman-based script and Cyrillic script. Logically, OmegaWiki will eventually contain Expressions of South Azerbaijani text in each of these scripts, presumably with the same Language code. ISO15924 defines four-letter codes for many scripts.
Scripts change over time. For instance, both Japanese and Chinese have reformed their standard character forms in the 1940's. Thus there are some words in both languages which had one Expression before the reform, and a different Expression after the reform, both linked to the same DefinedMeaning. This has similar consequences to OmegaWiki as historical spellings of English words.
Orthography is the set of rules for expressing a certain language in written form, including the choice of script and how that script is used. Orthography changes over time. For instance, in 1996 Germany, Austria, and Switzerland started to change the rules for writing German.
 Languages which are not written
Some languages, such as "ase" American Sign Language are neither spoken nor written. Although OmegaWiki is a dictionary of written expression, it is a goal eventually to catalog sign languages as well. Thus, some non-written languages are in scope for OmegaWiki.
Sutton SignWriting script provides a way to record sign languages in writing. However, Sutton SignWriting is not yet encoded in Unicode, so it is technically difficult to record it in the database. ISO 639-3 does have language codes for multiple sign languages.
 Details of OmegaWiki's use of ISO-639-3
OmegaWiki will make use of the ISO-639-3 qaa through qtz codes that are reserved for local use that is possible within the standard for specific information. This helps us deal with expressions that have a "grammar" but are not necessarily a language used for general communication. ISO 639-3 says these codes are for "cases in which there is no suitable existing code".
 List of languages in use on OmegaWiki
- Editable languages is a page with a list of the editable languages (automatically generated).
- Omegawiki.org's statistics shows the number of expressions, definitions etc. in each language.
If you would like to edit in a language that is not yet available in OmegaWiki, you can ask for it in the International Beer Parlour. Editable languages can be added by bureaucrats.