On 16 August 2011 18:19, Asmus Freytag <asm...@ix.netcom.com> wrote: >> "These stacks are highly unusual and are considered beyond the scope >> of plain text rendering. They may be handled by higher-level >> mechanisms". > > The question is: have any such "mechanisms" been defined and deployed by > anyone?
In my opinion, until someone produces a scan of a Tibetan text with multiple consonant-vowel sequences, and asks how they can represent it in plain Unicode text there is no question to be answered. Chris Fynn asked about certain non-standard stacks he was trying to implement in the Tibetan Machine Uni font in an email to the Tibex list on 2006-12-09, but these didn't involve multiple consonant-vowel sequences (one stack sequence was <0F43 0FB1 0FB1 0FB2 0FB2 0F74 0F74 0F71> which would be reordered to <0F42 0FB7 0FB1 0FB1 0FB2 0FB2 0F71 0F74 0F74> by normalization which would display differently). Other non-standard stacks that I have seen involve horizontal progression within the vertical stack (e.g. yang written horizontally in a vertical stack). More recently, the user community needed help digitizing Tibetan texts that used the superfixed letters U+0F88 and U+0F89 within non-standard stacks, resulting in a proposal to encode additional letters (http://std.dkuug.dk/jtc1/sc2/wg2/docs/n3568.pdf). None of these non-standard stack use cases involved multiple consonant-vowel sequences, and I'm not sure whether I have ever seen an example of such a sequence. I have learnt that there is little point discussing a solution for a hypothetical problem, because when the real problems arise they likely to be something different. Andrew