This property defines the Unicodes which has Jamo Short Name as JJ
Characters like ᄍ, etc. are listed under JJ Jamo Short Name.
1 Characters are present in JJ Jamo Short Name starting with the Unicode point U+110D that represents the character ᄍ.
Currently, as per latest version 15.0.0, Unicode supports 53 number of Jamo Short Name. Here are a few examples - A,AE,B, etc.