This property defines the Unicodes which are Cluster Break between a base character and a trailing non-spacing mark
Characters like ᆨ,ᆩ,ᆪ, etc. are listed under Tone Grapheme Cluster Break.
137 Characters are present in Tone Grapheme Cluster Break starting with the Unicode point U+11A8 that represents the character ᆨ.
Currently, as per latest version 15.0.0, Unicode supports 14 number of Grapheme Cluster Break. Here are a few examples - Base,Carriage Return,Control Neutral, etc.