This property defines the Unicodes which belongs to Cyrillic Extended C block
Characters like ᲀ,ᲁ,ᲂ, etc. are listed under Cyrillic Extended C Block.
10 Characters are present in Cyrillic Extended C Block starting with the Unicode point U+1C80 that represents the character ᲀ.
Currently, as per latest version 15.0.0, Unicode supports 328 number of Block. Here are a few examples - Latin Extended E,Adlam,Aegean Numbers, etc.