NOTE: One possible default internal representation that was compatible with UTF16 but allowed all possible chars in UCS4 would be to take a more-or-less unused range of 2048 chars (not from the private area because Microsoft actually uses up most or all of it with EUDC chars). Let's say we picked A400 - ABFF. Then, we'd have: 0000 - FFFF Simple chars D[8-B]xx D[C-F]xx Surrogate char, represents 1M chars A[4-B]xx D[C-F]xx D[C-F]xx Surrogate char, represents 2G chars This is exactly the same number of chars as UCS-4 handles, and it follows the same property as UTF8 and Mule-internal: 1. There are two disjoint groupings of units, one representing leading units and one representing non-leading units. 2. Given a leading unit, you immediately know how many units follow to make up a valid char, irrespective of any other context. Note that A4xx is actually currently assigned to Yi. Since this is an internal representation, we could just move these elsewhere. An alternative is to pick two disjoint ranges, e.g. 2D00 - 2DFF and A500 - ABFF. Bill Tutt wrote: -- Ben In order to save my hands, I am cutting back on my mail. I also write as succinctly as possible -- please don't be offended. If you send me mail, you _will_ get a response, but please be patient, especially for XEmacs-related mail. If you need an immediate response and it is not apparent in your message, please say so. Thanks for your understanding. See also http://www.666.com/ben/typing.html.