2013-03-09 21:30, Asmus Freytag wrote:
I believe the Unicode Standard should be fixed by explicitly removing all suggestions in the text that the raised decimal point is unified with 002E.
That would be a good move if agreement can be found on the recommended coding of the middle dot.
Second, the standard should be amended by identifying which character is to be used instead for this purpose. It might be something like 00B7.
There are several reasons why that would be a bad move. First, 00B7 is a seriously overloaded character already. Second, it’s a middle dot, which may differ from a raised dot. Mixed-language documents may well contain both British number notations and occurrences of middle dot in various contexts, and it should be possible to make them appear as different.
Due to another unfortunate unification (or semi-unification), 0387 (Greek ano teleia) has been defined as canonical equivalent to 00B7, with the note “00B7 is the preferred character”. This means that glyph design for 00B7 needs to take this into account, and since Greek ano teleia isn’t really a middle dot (rather, an upper dot, appearing roughly around the x-height of a font, rather than at half of x-height, which is a natural position for middle dot).
The code chart comment on 002E (full stop) says: “may be rendered as a raised decimal point in old style numbers”. But checking a few fonts that use the OpenType feature for old style numbers (onum), I was unable to find any that has such a glyph selectable that way.
I wonder what character and techniques British publishers use to produce notations with a raised dot. Is it 002E, with typographic tools used to raise it, or is it 00B7?
I believe that is entirely possible, and non-disruptive, insofar as numeric use of 00B7 does not exist for any purpose other than showing a raised decimal point
I’m afraid there is mathematical use of 00B7. It is tempting to use it as a multiplication dot (as in 2 · 2, meaning the same as 2 × 2), especially if you are limited to using ISO Latin 1 repertoire or you find 00B7 essentially simpler to type than 22C5 (dot operator). Standards have been vague or ignorant of the issue (now ISO 80000-2 explicitly defines the multiplication dot as 22C5, but I wonder how many people know about this).
Especially if the middle dot is used as multiplication symbol without spaces around it, confusion would be guaranteed.
If that alternative is deemed not acceptable, the only remaining choice would be to add a new character. (I would recommend that only as the last resort).
I would recommend that as the right approach. It will not fix the problem anytime soon, but it’s a move in the right direction.
Yucca
