Problem in defs for Fake A-Label
Mark Davis
mark at macchiato.com
Mon Mar 23 18:57:02 CET 2009
John, there is a problem in defs with Fake A-Label
Defs:
Some labels that are prefixed with "xn--" may not be the output of
the Punycode algorithm, or may fail the other tests outlined below or
violate other IDNA restrictions and thus are also not valid IDNA-
labels. They are called FAKE-A Labels for convenience.-
Protocol:
Fake A-labels, i.e.,
invalid strings that appear to be A-labels but are not, MUST NOT be
placed in DNS zones that support IDNA.
But in ASCII-LABEL for Fake A-Label you have:
(3) Note that a Fake A-Label has a prefix "xn--"
but the remainder of the label is NOT the valid
output of the Punycode algorithm.
I think what we should have is: XN-Label (as defined), with a subclass
P-Label (the remainder is valid punycode), with a subclass A-Label
(corresponds to U-Label). Then we have:
- P-Label corresponds 1:1 with Unicode Label (any Unicode string with at
least one non-ASCII character)
- A-Label corresponds 1:1 with U-Label
A Fake A-Label is {XN-Label - A-Label}, and not {XN-Label - P-Label}, which
is what (3) says.
Mark
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.alvestrand.no/pipermail/idna-update/attachments/20090323/35983bbd/attachment.htm
More information about the Idna-update
mailing list