This property defines the Unicodes which belongs to Miscellaneous Mathematical Symbols B block
Characters like ⦀,⦁,⦂, etc. are listed under Miscellaneous Mathematical Symbols B Block.
128 Characters are present in Miscellaneous Mathematical Symbols B Block starting with the Unicode point U+2980 that represents the character ⦀.
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.