by Michael S. Kaplan, published on 2005/02/12 18:02 -05:00, original URI: http://blogs.msdn.com/b/michkap/archive/2005/02/12/371737.aspx
On the Unicode List, in talking about these two characters, John Cowan said:
They look weird. The U+02EB (yang) one looks like reversed or turned 33, and the U+02EA (yin) one like turned 55 or reversed 11, none of which makes much sense. I wonder if the glyphs haven't been munged somewhere.
Looking at the two characters:
U+02eb ˫ MODIFIER LETTER YANG DEPARTING TONE MARK
U+02ea ˪ MODIFIER LETTER YIN DEPARTING TONE MARK
They do seem a little odd (use the links if you do not see the characters).
Luckily, Ken Whistler came to the rescue and explained where these characters came from:
U+02EB and U+02EA come from the TCA submissions regarding for Minnan and Hakka languages, for use with extended Bopomofo. You can find examples in those documents. They are mixed there with other Bopomofo tone diacritics. See WG2 N1713 for the initial submission. (1998-03-16)
Here is the scheme as represented there, with Taiwanese examples:
Yin level (unmarked) tong1 'east'
Yin rising U+02CB (with Bopomofo glyph) tong2 'a surname'
Yin departing U+02EA tong3 'freeze'
Yin entering (unmarked) tong4 'supervise'
Yang level U+02CA (with Bopomofo glyph) tong5 'child'
Yang departing U+02EB tong7 'cave'
Yang entering U+02D9 tok8 'poison'
In Bopomofo these tone marks are typeset in a separate vertical line to the right of the vertical line of Bopomofo. In horizontal typesetting, they are either over the top of the Bopomofo or set at the upper-right shoulder of the Bopomofo character representing the 'final' of a syllable.
It is possible that they were originally designed by a dyslexic based on the Chao tone letters, but no, they are not really intended to be used as particular values of those or as an augmentation of those tone letters. Instead, as I indicated, they are used with another collection of tonal diacritics for extended Bopomofo.
So no, they glyphs haven't been munged. But these obviously need better annotation for the names list.
--Ken
P.S. Is somebody collecting the 'Every character has a story' stories?
Well, collecting may be something of an overstatement. But I am trying to post some from time to time based on Unicode List conversations....
By the way, no additional annotation for the names list has yet been done. :-)
This post brought to you by "˫" and "˪" (U+02ea and U+02eb, a.k.a. MODIFIER LETTER YIN DEPARTING TONE MARK and MODIFIER LETTER YANG DEPARTING TONE MARK, for obvious reasons)