(Sorry for the havock my attemted subscription caused - I can only apologize.)

I am looking for documentation of cyrillic alphabetical enumeration, and wondered if someone could point me to either how I can check how LaTeX does it, and/or if someone can tell me - or point to a resource.

For instance, is the ёЁ (io/IO) used in alphabetical enumeration? I suppose not. But perhaps there are different usage?

Else, all leters are used, I suppose (except hard and soft sign), and in upper and lower-case?
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leif