This property defines the Unicodes which belongs to Cyrillic Supplement block
Characters like Ԁ,ԁ,Ԃ, etc. are listed under Cyrillic Supplement Block.
48 Characters are present in Cyrillic Supplement Block starting with the Unicode point U+0500 that represents the character Ԁ.
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.