A few languages (ar, arz, ko, lrc, ur) have localized the special page name
"OAuth", which means that in these languages requests to Special:OAuth
result in redirects. This breaks OAuth-signed requests to
Special:OAuth/identify, unless they use the localized name, and in general
developers shouldn't be expected to be aware of that.
To reduce confusion, starting next week special page name localization will
be disabled for Special:OAuth when the request is OAuth-signed, which means
that sending requests to Special:OAuth/identify will always work, and
sending requests to localized versions (such as 특수:MWO인증/identify on
kowiki) will stop working. If you have been doing the latter, you need to
update your code.