This property defines the Unicodes which belongs to Rejang block
Characters like ꤰ,ꤱ,ꤲ, etc. are listed under Rejang Block.
38 Characters are present in Rejang Block starting with the Unicode point U+A930 that represents the character ꤰ.
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.