Cyrillic Extended-C is a Unicode block containing Cyrillic characters mostly for facsimile reprinting Old Believer service books. The first 9 characters are (contextual) graphic variants of standard Cyrillic rather than distinct letters.
History The following Unicode-related documents record the purpose and process of defining specific characters in the Cyrillic Extended-C block:
Version Count L2 ID WG2 ID Document 9.0 U+1C80..1C88 9 N4645 doc) 16.0 U+1C89..1C8A 2
References