This property defines the Unicodes which belongs to Vertical Forms block
Characters like ︐,︑,︒, etc. are listed under Vertical Forms Block.
11 Characters are present in Vertical Forms Block starting with the Unicode point U+FE10 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.