My point is that characters such as 02B0, 02B2, and 02E0 are already used in the same fashion as the newly proposed Indo-European characters. Therefore, it's not clear to me why there should be any objection to the latter.
Because any mathematical alphanumberic character can appear superscripted in mathematics; does that mean that we need to create superscripted characters for all of them? If these are part of a small, closed set, like U+02B0, then it's appropriate to encode them; but if just any character can appear superscripted or subscripted, then it goes outside Unicode, and needs to be dealt with in markup.
Unicode started with a small and apparently closed set of superscript Latin letters. This set has now grown to include all or almost all of the basic Latin alphabet, as well as a good number of capital letters, Greek letters and non-basic Latin letters, many of them in the Phonetic Extensions block. The way in which these have been added piecemeal means that they are non-contiguous and confusing. My point in intervening on this topic is to suggest that more forethought is given to subscript letters, by allocating a contiguous block into which they can all be fitted so that they can all be used without having to be justified individually. So I would object to the proposal N2705 because it proposed encoding just four such subscript letters in a space which is not large enough for even one whole alphabet.
According to the Roadmap, the Phonetic Extensions block can already be extended to cover 1D80-1DBF. I would suggest reserving this extension block for subscript letters, which gives space for upper and lower case subscript basic Latin alphabets and some extra characters. There is still a question of where subscript Greek letters might go; there is just space for a lower case Greek alphabet in the Greek and Coptic block, but this is not contiguous.
Alternatively, let's leave all subscripting to markup.
-- Peter Kirk [EMAIL PROTECTED] (personal) [EMAIL PROTECTED] (work) http://www.qaya.org/
