Andre Engels wrote:
This might be an idea for commons, or meta. But I would not like to have it on other projects. In my opinion the fact that someone goes to a certain language Wikipedia or Wiktionary is more evidence of their language wishes than their Accept-language.
Andre Engels (who has felt no need to change interface language on the dozens of Wikipedias he has been editing, but would be much interested in a single login)
I think the suggestion is that the interface language should be chosen as follows, in the order given: 1: User preference of logged in user, if set 2: Language of the Wiki itself, if one is defined (all Wikipedias, Wiktionaries, etc.), if 1 is not defined. 3: Accept-language of their browser, if neither 1 or 2 is defined 4: English, if their Accept-language is not supported (on the basis that it is the world's most common language, counting both first and second language users)
This seems like a pretty safe bet, as it should meet the principle of least astonishment for the largest possible number of users.
-- Neil