[idn] Proposal to re-prohibit U+3002

[Paul Hoffman / IMC <phoffman@imc.org>]

Greetings again. James Seng pointed out a difference between 
nameprep-00 and nameprep-02 that has a significant impact on Asian 
input mechanisms. In many Asian IMEs, typing the "period" character 
on the keyboard enters U+3002 into the IME. Clearly, the user is 
doing this to enter a period (U+002E), and the only way to actually 
enter U+002E is to toggle between their native characters and ASCII 
for that single character.

U+3002 was prohibited in nameprep-00 because of its similarity to 
U+002E, but it is allowed in nameprep-02. The nameprep design team 
has tentatively agreed that we should revise nameprep to prohibit 
U+3002, not because it looks like U+002E (in fact, in many fonts, 
they look different), but because it is used as if it were U+002E in 
input mechanisms. This would allow IME makers to safely map U+3002 to 
U+002E *before* doing nameprep without worrying about preventing 
users from accessing legitimate host name parts.

Just to be clear, this is not "fixing" something in 10646/Unicode, 
but making it easier for Asian IMEs to do the right thing with name 
parts.

Comments?

--Paul Hoffman, Director
--Internet Mail Consortium