#3 problem with cyrillic in nicknames

[Konstantin Shabanov]

Ezbounce don't see peoples who change nick from non-cyrillic to cyrillic
before part and join.
I got this on Rusnet/koi8-r.

[Murat Deligonul]

Logged In: YES
user_id=1527331
Originator: NO

Unfortunately the IRC parser rejects nicknames that do not meet the strict definition in the RFC.

How does the RusNet server inform clients that it will be using non-standard nicknames?