> > (D) None of the above > > True. I would like to add to Jim Allan's excellent explanation here that the relevant coding domain for these decisions of same or different for encoding a particular character is the *script* in question.
The first decision that needs to be taken is whether a particular writing system mooted for consideration for encoding of its characters constitutes a distinct script or not in the sense used by Unicode/10646. If the answer is no, and the writing system is considered, for example, to be a stylistic or historic variant of a script already encoded, then considerations of unification *within* a script come into effect. If it turns out that the particular writing system in question contains characters beyond whatever have already been encoded for that script, then those characters become valid candidates for additional encoding. Recent examples can be found among the various Arabic character additions for West African languages written in the Arabic script. If the answer is yes, then an entirely separate script will be encoded. This script must then have *all* of its characters encoded, even where there might be considerable overlap in appearance and/or linguistic function for some subset of those characters, for either historic reasons or merely by coincidence. An example of this can be see in Old Italic, many of whose letterforms are clearly related to early Greek and to early Latin. Nevertheless, once Old Italic was distinguished as a script to be encoded, rather than just another variant alphabet (or set of alphabets, actually) of archaic Greek, then that determines the further decisions about the repertoire to be encoded. It doesn't make any sense to just pick out those *particular* Old Italic letters that happen to be distinguishable in shape (U+10307 OLD ITALIC LETTER HE) or in function (U+1030E OLD ITALIC LETTER ESH) from Greek letters and to encode only them. Where people seem to get most hung up the first time they encounter UTC decisions about encoding characters (particularly for scripts, as opposed to symbol sets) is on these lookalike and/or historical relation questions. Hence the eternal newbie questions about Latin, Greek, and Cyrillic capital "A", for example. --Ken
