This property defines the Unicodes which belongs to Old Turkic block
Characters like 𐰀,𐰁,𐰂, etc. are listed under Old Turkic Block.
74 Characters are present in Old Turkic Block starting with the Unicode point U+10C00 that represents the character 𐰀.
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.