MatroskaName
One name of an edition or chapter in its languages.
A chapter's display states its language either as BCP 47 tags (ChapLanguageBCP47) or as ISO 639-2 codes with optional countries (ChapLanguage, ChapCountry). When it has a BCP 47 tag the other two are ignored, as RFC 9559 says, so languages holds the tags and countries is empty; otherwise languages holds the codes, eng when it states none. An edition's display states BCP 47 tags only, and its languages is empty when it states none.