When creating a new Lexeme, the lexeme's language has to be specified by selecting an Item that represents the language. Also, the lexeme's lemma needs to have a language code associated.

For convenience, and to avoid confusion, the lemma's (default) language code should be derived from a statement on the language item (P219: ). If the item does not specify a language code (in a statement with appropriate rank), Special:NewLexeme could refuse to create the Lexeme, or ask for a language code for the lemma to be specified explicitly.