Please add the five language codes {rm-rumgr, rm-sursilv, rm-sutsilv, rm-vallader, rm-puter} to the list of language codes supported for monolingual text values. I’m filing this request for making it possible to enter lexemes in Wikidata.
As per the IETF BCP47 language subtag registry [https://www.iana.org/assignments/language-subtag-registry/language-subtag-registry], rm-rumgr is the BCP47 language code for Rumantsch Grischun; rm-surmiran for Rumantsch Surmiran; rm-sutsilv for Rumantsch Sutsilvan; rm-sursilv for Rumantsch Sursilvan; rm-vallader for Rumantsch Vallader; rm-puter for Rumantsch Puter.
From a lexicographical perspective, these language variants are quite distinct: they have different vocabularies, different phonology, and inflection. (That’s also why they have different subtags in IETF BCP47). For reference, see http://www.pledarigrond.ch which has separate dictionaries for each variant.
In Wikidata, rm-rumgr is Q688873; rm-surmiran is Q690216; rm-sutsilv is Q688272; rm-sursilv is Q688348; rm-vallader is Q690226; rm-puter is Q688309.