This property defines the Unicodes which belongs to Katakana block
Characters like ゠,ァ,ア, etc. are listed under Katakana Block.
96 Characters are present in Katakana Block starting with the Unicode point U+30A0 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.