An user from the nowiki added labels and got "no" as language code , as in [[ https://www.wikidata.org/w/index.php?title=Q18528095&type=revision&diff=260653338&oldid=258560096 | this edit ]]. When I checked this I found that both "nb" and "no" are in the list on [[ https://www.wikidata.org/wiki/Special:Preferences#mw-prefsection-personal | Special:Preferences#mw-prefsection-personal ]] as "norsk bokmål". The language code "no" is a macrocode for both Norwegian Bokmål and Norwegian Nynorsk. The code "nb" is the content code we are using at nowiki.
I have asked the user [[ https://www.wikidata.org/wiki/User:Asav | Asav ]] if he has selected the "no" language code in preferences. An other possible problem is that he has "no" in the Babel boxes, will this create an entry for "no" in the signature section?