Quoting Francisco:
I wonder what others think about the ideas in this document posted to the latin team. Apologies to Harald for putting you in the spot.
I also agree with Harald’s emphatic conclusion. There is, however, a single case in the Latin code point repertoire where different abstract characters at separate code points are commonly represented with the same glyph, thus properly requiring special consideration in the VIP study. This is: U+01DD ; ǝ # LATIN SMALL LETTER TURNED E U+0259 ; ə # LATIN SMALL LETTER SCHWA Although there is no everyday writing system including the one of them that also includes the other, since they are both PVALID it is to be expected that some registries will also support them both. (Remember that gTLDs rarely have any specific language nexus and serve a polyglot registrant base.) They are, however, conceptually distinct and cannot be treated as variants of each other in any algorithmic (or, for that matter, linguistic) sense. To be sure, this necessitates particularly rigorous consideration before adding either of them to a local repertoire of supported code points. That need can be flagged in any exhaustive tabulation of PVALID code points for the Latin script. This would require an informational annotation, and likely some form of narrative recommendation, but there is no stronger "variant" issue that needs to be accommodated. The set of counterarguments that can be typified by, "Yes, but I sure think that 'æ' and 'ae' are confusingly similar and therefore expect that other users would, as well", all require contextual modulation. The 'æ' is an atomic element of the Norwegian alphabet (and others) and any suggestion that the VIP study might make of need for its canonical equation to 'ae' would be met with a dismissive giggle at best, and taken as sheer cultural effrontery at worst. In either case, it would risk our output being disregarded. /Cary