I wonder why there is no officinal drachma sign present in Unicode so far. It seems really odd.
Other old weight measurement signs are there: scrupule ℈ (2108), libra ℔ (2114), ounce ℥ (2125). There is also a character for uncia semis 🝳 (1F773) meant to be a sort of ligature, and, nota bene, a character for drachma semis 🝲 (1F772) which is shown as a compound glyph. Especially in the light of the latter I find it illogical that the actual drachma is not to be found anywhere. It is a character very well attested in historic materials.
– OK, the shape of it resembles the latin ezh ʒ Ʒ (0292, 01B7). But that seems hardly to justify the omission of the dram. Ezh is a bicameral letter, it has other function and technical behavior than the drachma. The dram sign is a unicase ideographic character which is likely to demand different typographical treatment than the letters it looks so similar to, for instance its width in relation to other measurement signs or even figures.
Am I missing something important? Any thoughts?
0292 – lowercase ezh
01B7 – uppercase Ezh
F2E6 – Drachma sign, MUFI encoding (PUA!)
1F772 – half drachma
2125 – Ounce sign
1F773 – half ounce (ligature)
1F713 – cinnabar sign
Comments
EDIT:
Sorry, I misread. You are referring to the unit of volume not currency. The unicode standard recommends using U+0292. Yes, that would be a bicameral lowercase character, but this is no different from many other units of measure which employ latin characters as abbreviations (e.g. mm stands for millimetre, MM does not). The separate code points for other units of measure (Kelvin, Ångstrom, various CJK codepoints) are just there for compatability with pre-unicode codepages AFAIK.
🝲 (1F772) is actually nothing else than a combination of ʒ (0292) and ß (00DF; the ß stands not only for the German Eszett but also for the Latin Abbreviation ſ-s for “ſemis“ – half). By Unicode’s own policy there is actually no case for neither 1F772 nor 1F773 since the expressions can be fully represented by the appropriate sequences.
Again, I am confused here. This would be true, if those two symbols were used as ligatures within text. If they're used as symbols for half an ounce and half a dram instead, so that they appear in a distinctive style, then the sequences of corresponding characters won't completely represent them. That would be like saying that U+2133 doesn't belong in Unicode, since the letter M is already present at another codepoint.
These are good reasons in favour of unifying dram with ezh. As for these reasons given for not unifying...
There are several cases of an uppercase or lowercase character from a bicameral pair being used a symbol for some kind of unit and in which case mapping becomes inappropriate in that usage. (In fact, the Unicode Technical Committee just last week made this response to feedback regarding case mapping of Greek letters used as units.) For example, "ms" and "MS", when used as units, represent entirely different units. And just as the usage context can bring some implications for case mapping, it shouldn't be surprising if a usage context might have typographic implications, such as the need for tabular widths.
From a Unicode perspective, there's long-standing precedent for not accepting these as sufficient reasons to dis-unify.