Hmm, this appears to have already been changed in August: r55089

and that change is live and works fine on other wikis.

It looks like you've got a bunch of local messages overriding a lot of the defaults, probably from the Latin-based translations being built on-wiki:
http://tt.wikipedia.org/wiki/%D0%9C%D0%B0%D1%85%D1%81%D1%83%D1%81:AllPages/MediaWiki:

Local admins need to go through and delete the ones that are no longer needed, and update those which are explicitly customized to use the Cyrillic script.

timming wrote:

(In reply to comment #1)

Hmm, this appears to have already been changed in August: r55089

and that change is live and works fine on other wikis.

It looks like you've got a bunch of local messages overriding a lot of the
defaults, probably from the Latin-based translations being built on-wiki:
http://tt.wikipedia.org/wiki/%D0%9C%D0%B0%D1%85%D1%81%D1%83%D1%81:AllPages/MediaWiki:

Local admins need to go through and delete the ones that are no longer needed,
and update those which are explicitly customized to use the Cyrillic script.

Thanks. We are going to transliterate these pages soon.

timming wrote:

I've removed all non-Cyrillic translations. Everything is OK now.