CJK-specific letter forms for these abbreviations/units should be left as is. They are kept for compatibility reason and I don't see a reason to change them to upright which would contradict their legacy usage. The SI brochure does not apply to these legacy square presentations (which would be enyway incomplete for many SI units and derived units). Anyway it is still possibly to create a CJK font that would map them with upright mu, I don't think it would cause major damages. When using SI units these characters are not used, and the standalone Latin characters should not use any ligature or special form, but they may still be styled separately if one needs to distinguish SI units from abbreviations or actual words (so it's possible to change the font-faminly, font style specifically for the unit, or for the whole anatity with the number and unit symbol, or a whole formula, to isolate them fro mthe rest of normal text: this is what CJK fonts already do for some of these units or some common abbrevs, so for me these CJK compatibility characters are already such explicit style modifications applied to Latin, these characters may still be partly restyled (color, weight, but probably not italic/obliique which would leave them intact, just like the CJK wide and narrow variants of Latin letters, as they have to keep their CJK square or half-square metrics).
2018-06-19 9:57 GMT+02:00 Ivan Panchenko via Unicode <unicode@unicode.org>: > Is there a reason why the mu does not appear upright in the reference > glyph for U+3382 ㎂, U+338C ㎌, U+338D ㎍, U+3395 ㎕, U+339B ㎛, U+33B2 ㎲, > U+33B6 ㎶ and U+33BC ㎼ of the CJK Compatibility code chart? I also see it > this way in fonts such as Junicode, Unifont and WenQuanYi Zen Hei while > U+00B5 µ is displayed upright there. “Prefix symbols are printed in roman > (upright) type, as are unit symbols, regardless of the type used in the > surrounding text, […].” (SI Brochure) > > By the way, U+3396 ㎖ is displayed with a capital M instead of a small m in > Droid Sans Fallback (as included in my Ubuntu system) and Arial Unicode MS, > suggesting “megaliter” instead of “milliliter”! The latter font has not > been developed further since version 1.01, does someone know about the > former? Droid fonts can be purchased at fonts.com but I cannot find the > fallback font there (so maybe contacting Ascender would be of no use). > > Best regards > Ivan >
