ISO 639 is a set of international standards that lists short codes for language names. The following is a complete list of three-letter codes defined in part two (ISO 639-2) of the standard,^[1] including the corresponding two-letter (ISO 639-1) codes where they exist.

Where two ISO 639-2 codes are given in the table, the one with the asterisk is thebibliographic code (B code) and the other is the terminological code (T code).

Entries in theScope column distinguish:

• individual language;
• collections of languages connected, for examplegenetically or by region;
• macrolanguages.

TheType column distinguishes:

• Living (natural languages in current use);
• Historical (distinct from their modern form);
• Extinct in recent times;
• Constructed.

for individual languages, and

• Genetic;
• Genetic-like;
• Geographic (for regional language groups).

for collectives. The differences between genetic and genetic-like are vague, but usually the former comprises more individual languages than the latter, while the latter comprises more language families than the former.

The standard includes some codes for special situations:^[1]

• mis, for "uncoded languages";
• mul, for "multiple languages";
• qaa–qtz, a range reserved for local use;
• und, for "undetermined";
• zxx, for "no linguistic content; not applicable".