Unicode points 2090–2094 are described as subscript a, e, o, x and schwa. The official Unicode chart says nothing about the usage of those glyphs, and I can't seem to find information on them elsewhere. Can anyone shed some light on this?
These were put into Unicode for historical linguistics, where there can be an obligatory semantic difference between the subscript and non-subscript letters:
http://std.dkuug.dk/jtc1/sc2/wg2/docs/n2788.pdf
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