This property defines the Unicodes which belongs to CJK Compatibility block
Characters like ㌀,㌁,㌂, etc. are listed under CJK Compatibility Block.
256 Characters are present in CJK Compatibility Block starting with the Unicode point U+3300 that represents the character ㌀.
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.