I have two questions about this.1) In UAX #44, it says for information about the Grapheme_Base property, to see UAX #29, but that document doesn't mention this property.
2) The definition in UAX #29 for both legacy and extended grapheme clusters effectively says that any Gc=Cn code points followed by any number of grapheme_extend code points is a grapheme cluster. Is that what is meant? I notice that Grapheme_Base excludes Cn code points.
