This property defines the Unicodes which belongs to CJK Unified Ideographs Extension D block
Characters like 𫝀,𫝁,𫝂, etc. are listed under CJK Unified Ideographs Extension D Block.
223 Characters are present in CJK Unified Ideographs Extension D Block starting with the Unicode point U+2B740 that represents the character 𫝀.
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.