The redirects table in connects Wikipedia language codes to the corresponding code used on the English Wiktionary. records this relationship for ISO codes. For instance, all of bs (Bosnian), hr (Croatian), sr (Serbian), cnr (Montenegrin), kjv (Kajkavian) are placed under the header for sh (Serbo-Croatian) in Wiktionary entries. See for instance, the word that Kajkavian is named after. The subsumed codes should still be used in language-tagging on Wikipedia.