These codes represent collections of languages. See http://www-01.sil.org/iso639-3/scope.asp. Codes here appear in ISO 639–2 and/or ISO 639–5, not ISO 639–3, so under Language proposal policy, none of these codes are valid for starting new Wikimedia projects.
- The last working test with a collective code was closed in February 2018.
- As for the three existing wikis that use such codes, although they presently continue to use such codes, we intend to move them to other codes over time:
- Bihari Wikipedia: Their community has requested to rename to Bhojpuri Wikipedia using bho.wikipedia.org, see phab:T41968, note that ISO 639-1 bh is deprecated in 2021, and now this named collective languages only has ISO 639-2 bih;
- Nahuatl Wikipedia and Wiktionary: This problem is very complex. See discussions on Incubator at Category talk:Incubator:Nahuatl languages and on Meta-Wiki at m:Requests for comment/Rename nah.wikipedia to nci.wikipedia.