I had an idea for a feature to allow any language user to go to any other language wiki and be able to use the namespaces they recognize.
The idea would be that a user from it.wp could go to fr.wp and when visiting Utente:... (Utente is User in Italian) whether via search or direct address linking and end up on Utilisateur:... (French's User namespace)
This would be done by considering every possible localization of a namespace as an alias in all languages. So on fr.wp Utente, User, etc... would all be aliases for Utilisateur. Additionally since namespaces are dependent on the user rather than the content for logged in users we could start displaying localized namespace names to help the user around and not have to worry about issues that if they copy&paste or whatever it wouldn't be valid.
We've got a massive localization cache, and it's possible we might find a way to make a feature like this possible, so that wasn't an issue to stop this idea. But there was a slim possibility that words used for namespaces might conflict with what other languages use. That sounded so unlikely that I wrote a script to scan every language we have for all available namespace names and what they map to and see if the same text is used for different namespaces in any languages.
And the dooming news, there are some conflicts.
"Stampa" is NS_TEMPLATE in Aln (Gheg Albanian) and Sq (Albanian) and NS_FILE in Mt (Maltese). And Datoteka is NS_FILE in Bs (Bosnian), Hr (Croatian), and Sh (Serbocroatian), but NS_MEDIA in Sl (Slovenian).
So our only options are (probably in order of simplicity/likelihood first ;) ): A) Drop this feature idea. B) Find a way to deal with collisions and accept there may be some bugs an confusing behavior for users. C) Implement this while making use of lots of language heuristics like Accepts-Language, Geolocation, and other things that will hurt caching. D.a) Drop support for either Maltese or Albanian languages and Slovenian or Croatian languages. D.b) Convince everyone who speaks these languages to use a different word. D.c) Commit genocide and wipe those languages off the face of the earth and erase them from the history books. E) Implement a brain-neural interface and require use of it while browsing Wikipedia so that we can extract what the user 'actually' means and understands directly from their mind.