Please add the language code mn-Mong to the list of language codes supported for monolingual text values.
Usage example: {{lang|mn-Mong|ᠮᠣᠩᠭᠣᠯ ᠪᠢᠴᠢᠭ}} (idealy with {{MongolUnicode|{{lang|mn-Mong|ᠮᠣᠩᠭᠣᠯ ᠪᠢᠴᠢᠭ}}}} to be displayed vertically.
This is for traditionnal [[:en:Mongolian script]] (mongol bichig) support in [[Property:P1705]] of Wikidata.