This property defines the Unicodes which belongs to Latin Extended D block
Characters like ꜠,꜡,Ꜣ, etc. are listed under Latin Extended D Block.
197 Characters are present in Latin Extended D Block starting with the Unicode point U+A720 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.