There are various lists defining language codes for Wikibase. Some values in these lists are not suitable for the termbox on Wikidata.org. See T44396 for the general problem.
Sample: "no" isn't used on Wikidata, but is the domain name for no.wikipedia.org . Wikidata uses just "nb".
The idea is to add a configuration variable that allows to disable such language codes. Deletion of existing values should still be possible.
* Sample: "no" isn't used on Wikidata, but is the domain name for no.wikipedia.org . Wikidata uses just "nb".
* Other codes for an initial version of the variable: "bat-smg", "bh", "fiu-vro", "roa-rup", "simple", "zh-classical, "zh-min-nan", "zh-yue"
Despite efforts to clean this up by bot, the numbers of are currently at 500,000 (June 2021, see [[T44396#7150919]]).
This doesn't touch their use for lexemes or monolingual strings. For the later, see [[ https://gerrit.wikimedia.org/g/mediawiki/extensions/Wikibase/+/77708f720c08e9e252bbe011b214bce6d6c777e6/lib/includes/WikibaseContentLanguages.php#142 | DifferenceContentLanguages ]] with DefaultMonolingualTextLanguages