This property defines the Unicodes which belongs to Hangul Jamo Extended A block
Characters like ꥠ,ꥡ,ꥢ, etc. are listed under Hangul Jamo Extended A Block.
30 Characters are present in Hangul Jamo Extended A Block starting with the Unicode point U+A960 that represents the character ꥠ.
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.