This property defines the Unicodes which belongs to Latin Extended A block
Characters like Ā,ā,Ă, etc. are listed under Latin Extended A Block.
128 Characters are present in Latin Extended A Block starting with the Unicode point U+0100 that represents the character Ā.
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.