This property defines the Diacritic Unicodes which can be present at Top And Bottom And Right of the base character
Characters like ᬽ, etc. are listed under Top And Bottom And Right Indic Positional Category.
1 Characters are present in Top And Bottom And Right Indic Positional Category starting with the Unicode point U+1B3D that represents the character ᬽ.
Currently, as per latest version 15.0.0, Unicode supports 15 number of Indic Positional Category. Here are a few examples - Bottom,Bottom And Left,Bottom And Right, etc.