From TM-XML-Wiki

ISO 639-1:2002 language code extended with the value "Undefined"

AccountDebitKindType (Enumeration Type)
No	Enumeration Value	Definition
1	Undefined	Undefined
Union Member Type:		ISOLanguageCodeType
Type of:		RecordLanguageCode ApplicationLanguageCode SecondLanguageCode CorrespondenceLanguageCode

Translation

de - German

es - Spanish

fr - French

it - Italian

Implementation-Specific