Last modified: 2013-12-10 15:37:51 UTC
Set a default value for the language in Special:ItemByTitle based on the user language.
There is no language in ItemByTitle. Do you want to guess the target site based on the user language? That is not always a unique match.
WE can't really do this, because we have multiple sites per language now (wikipedia, wikivoyage, wikisource, ...)