This is a list of ISO 639-5 codes, including the code hierarchy as given in the ISO 639-5 registry.[1] The code und
(undetermined) from ISO 639-2 can be seen as top of the hierarchy (for example, und:aav
, und:euq:eu
). The hierarchy is not a complete genetic hierarchy; some of the collection codes are based on geography (like nai
) or category (like crp
) instead.