Locales/language valid options
The documentation doesn't advise anything regarding what languages/localses exist/are valid to be called.
language query string argument, but doesn't advise what is valid for a langauge.
Document the list of locales of if it matches a ISO, update documentation on endpoints using language/locale with a note about what is valid
Additional context or questions
Raised/queried on discord
All language parameters and return examples in the reference have been given context for valid or expected values.