For commentary written with Cyrillic.
Not recommended for use due to redundancy and impossibility of unambiguous definition.
Consider this tag for use only when it is either impossible to unambiguously determine the language (comments from one character or several unrelated characters, or as part of other languages), or when the Cyrillic in question is used for a non-Cyrillic-using language.
Otherwise, put only the language tag, such as: