This property defines the Unicodes which belongs to Enclosed Alphanumerics Supplement block
Characters like 🄀,🄁,🄂, etc. are listed under Enclosed Alphanumerics Supplement Block.
201 Characters are present in Enclosed Alphanumerics Supplement Block starting with the Unicode point U+1F100 that represents the character 🄀.
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.