This property defines the Unicodes which belongs to Enclosed Alphanumerics block
Characters like ①,②,③, etc. are listed under Enclosed Alphanumerics Block.
160 Characters are present in Enclosed Alphanumerics Block starting with the Unicode point U+2460 that represents the character ①.
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.