In linguistics, codification is the social process of a language's natural variation being reduced and features becoming more fixed or subject to prescriptive rules.
It typically means to develop a writing system, set up normative rules for grammar, orthography, pronunciation, and usage of vocabulary as well as publish grammar books, dictionaries and similar guidelines.
In some countries such codification is done by a body constituted by the state, such as the Académie française.
In a well-known model of language planning by Einar Haugen, codification is only the second step.
Codification is part of the corpus planning of a language, because the "body" of the language itself is being planned as opposed to status planning, where the prestige and usage of a language is enhanced:[5] Whether the codification is successful depends heavily on its acceptance by the population as well as its form of implementation by the government, e.g. promoting its prestige and spread, teaching the codified norm in school and language courses, and so on.