This property defines the Unicodes which belongs to Supplemental Private Use Area B block
Characters like ,, etc. are listed under Supplemental Private Use Area B Block.
2 Characters are present in Supplemental Private Use Area B Block starting with the Unicode point U+100000 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.