I am looking for the list of supported language codes for variations of Chinese. So far in API responses I found these:

zh
zh-cn
zh-hans
zh-hant
zh-hk
zh-tw
zh-mo
zh-sg

"Configure" link in "more languages" section leads to this page: https://www.wikidata.org/wiki/Help:Navigating_Wikidata/User_Options#Babel_extension

Which in turn refers to https://meta.wikimedia.org/wiki/Table_of_Wikimedia_projects#Projects_per_language_codes

But apparently there is no such values as 'zh-cn', 'zh-nans' etc.

How can I get the COMPLETE list of language codes (desirably with description) for Chinese that is supported by Wikidata?

Best regards,

Vlad