Asmus asks, "Which implementation makes the required context analysis to determine whether 002E is part of a number during layout? If it does make this determination, which OpenType feature does it invoke? Which font supports this particular OpenType feature?"
I haven't looked to see if our various OpenType engines analyze the context of 002E to treat numerical contexts in a special way. But both 002E and 002C (COMMA) are handled contextually in the build up of UTN #28 linear format mathematical expressions and in the rendering thereof. In particular, note that in nonnumerical contexts, period and comma are followed by some extra spacing in math zones, but as parts of numbers, that extra spacing is omitted. Also in RtL math, the period and comma are displayed LtR when part of a number, but RtL otherwise. So contextual analysis of these characters is quite important. Murray
