This ticket is to add language codes for the representations of lexemes and forms in Middle High German and Old High German.
As a number of identifiers have been proposed providing some authority control for lexemes in those languages, the omission of the ISO 639 codes for representations would be a glaring oversight as far as their completeness in importing goes. (There are presently 17 lexemes in goh and 29 in gmh, and the number of identifiers for each language is in the tens of thousands, for which having the codes to begin with would help.)