Macrolanguage

ISO 639-3 is an international standard for language codes. In defining some of its language codes, some are classified as macrolanguages, which include other individual languages in the standard. This category exists to assist mapping between another set of languages codes, ISO 639-2, and ISO 639-3. ISO 639-3 is curated by SIL International, ISO 639-2 is curated by the Library of Congress (USA).

The mapping often has the implication that it covers borderline cases where two language varieties may be considered strongly divergent dialects of the same language or very closely related languages (dialect continuums). It may also encompass situations when there are language varieties that are sometimes considered to be varieties of the same language and sometimes different languages for ethnic or political rather than linguistic reasons. However, this is not its primary function and the classification is not evenly applied. For example, "Chinese" is a macrolanguage encompassing many languages that are not mutually intelligible, but the languages "Standard German", "Bavarian German", and other closely related languages do not form a macrolanguage despite being more mutually intelligible. Other examples include Tajiki not being part of the Persian macrolanguage despite sharing much lexicon, and Urdu and Hindi not forming a macrolanguage. Basically, ISO 639-2 and ISO 639-3 use different criteria for dividing language varieties into languages, 639-2 uses shared writing systems and literature more whereas 639-3 focuses on mutual intelligibility and shared lexicon. The macrolanguages exist within the ISO 639-3 code set to make mapping between the two sets easier.

There are fifty-six language codes in ISO 639-2 that are considered to be macrolanguages in ISO 639-3. The use of this category of macrolanguage was applied in Ethnologue, starting in the 16th edition.

Some of the macrolanguages had no individual language (as defined by 639-3) in ISO 639-2, e.g. "ara" (Arabic), but ISO 639-3 recognizes different varieties of Arabic as separate languages under some circumstances. Others, like "nor" (Norwegian) had their two individual parts (nno Nynorsk, nob Bokmål) already in 639-2. That means some languages (e.g. "arb" Standard Arabic) that were considered by ISO 639-2 to be dialects of one language ("ara") are now in ISO 639-3 in certain contexts considered to be individual languages themselves. This is an attempt to deal with varieties that may be linguistically distinct from each other, but are treated by their speakers as forms of the same language, e.g. in cases of diglossia. For example,

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