This property defines the Unicodes which belongs to Khmer Symbols block
Characters like ᧠,᧡,᧢, etc. are listed under Khmer Symbols Block.
32 Characters are present in Khmer Symbols Block starting with the Unicode point U+19E0 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.