This property defines the Decomposition Type of the Unicodes as Enclosing Mark
Characters like ①,②,③, etc. are listed under Enclosing Mark Decomposition Type.
240 Characters are present in Enclosing Mark Decomposition Type starting with the Unicode point U+2460 that represents the character ①.
Currently, as per latest version 15.0.0, Unicode supports 18 number of Decomposition Type. Here are a few examples - Canonical Decomposition,Compatibility,Enclosing Mark, etc.