At 12:33 AM 1/27/02 -0800, Mark Davis \(jtcsv\) wrote: >>I find it fairly pointless to say that a font "supports" the variation >>selection sequence <U+03B8, U+FE00> if it does not provide a visual >>distinction from <U+03B8>; and such a distinction should be based on the >>entry description. Thus, of the following four fonts, only number 4 >>correctly supports the sequence <U+03B8, U+FE00>. (Of course, any real >>font would have designs for the two glyphs that were a bit more harmonious!)
I couldn't view your examples, but guessing at what they might have been, I'll risk an answer. The problem is that some of the distinctions for which variant selectors are used, are *needed only by a minority of users*. Some of the math variants (not PHI, or THETA, but the ones in StandardizedVariants) may only be needed by *some* math authors. Any requirement that by supporting VS1, one must restrict the glyph range of the unmarked symbol forces either a) the tail to wag the dog or b) many dogs to do without tail Case a is where fonts assume the most restrictive glyph choice for the unmarked symbol, so that they can be used by all users. This is bad since the restricted glyph range for the unmarked symbol may be a somewhat unnatural one. Given the expense of creating a math font, it may not make sense to do one that is not usable by all math authors. Case b is where fonts assert their choice of unmarked glyph and (because of the required contrast) choose not to support the VS1 form, since that's the form they want to use as the unmarked default. Given the expense of creating a math font, the sub-set of math authors may not have the werewithal to source a font for their needs, since most of the market can be covered by something that is 'good enough'. By explicitly defining a way to restrict the glyph range (via coding another character, or another VS sequence) it becomes easier to support groups with related needs, but different requirements in the face of variants. A./
