[whatwg] Unicode mappings for ⟨ and ⟩

[Øistein E. Andersen]

HTML5 currently maps ⟨ and ⟩ to
    U+3008 LEFT ANGLE BRACKET,
    U+3009 RIGHT ANGLE BRACKET,
both belonging to `CJK angle brackets' in
    U+3000--U+303F CJK Symbols and Puntuation.

HTML 4.01 maps them to
    U+2329 LEFT-POINTING ANGLE BRACKET,
    U+232A RIGHT-POINTING ANGLE BRACKET
from `Angle brackets' in the range
    U+2300--U+23FF Miscellaneous Technical.

Unicode 5.0 notes:
> These are discouraged for mathematical use because of their
> canonical equivalence to CJK punctuation.

It would probably be better to use
    U+27E8 MATHEMATICAL LEFT ANGLE BRACKET,
    U+27E9 MATHEMATICAL RIGHT ANGLE BRACKET
from `Mathematical brackets' in
    U+27C0--U+27EF Miscellaneous Mathematical Symbols-A,
characters that did not yet exist when HTML 4.01 was published.

This approach is suggested by
http://unicode.org/Public/math/revision-09/MathMap-9.txt:
> 27E8;	lang;	ISOTECH;	**	# ⟨	MATHEMATICAL LEFT ANGLE BRACKET
> 27E9;	rang;	ISOTECH;	**	# ⟩	MATHEMATICAL RIGHT ANGLE BRACKET

Moreover, the (few) browsers I have tested render
&lang/&rang, &#x2329/&#x232a and &#x27e8/&#x27e9 identically
or simalarly (as "<"/">" in approximative ASCII), whereas
&#x3008/&#x3009 are rendered as full-width East-Asian
characters (" <"/" >").

-- 
Øistein E. Andersen