Steve, > All of this writing can be encoded using 1280 code points. I > have a 12-bit encoding with bi-directional conversion with UTF-8 working > for planes 1, 15, or 16.
A minor point, but I suggest you not use "bi-directional" in that context. "Bidirectional" is a term of art in Unicode character encoding, and refers to the mixture of left-to-right and right-to-left rendering in scripts such as Hebrew and Arabic that are predominantly right-to-left, but which are interspersed with bits of text from other scripts or numbers that lay out left-to-right. What you mean by "bi-directional conversion" in a character encoding context is usually referred to as "roundtrip mapping". --Ken
