-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Section 3.1 of draft-yoneya-precis-mappings states:

   Width mapping will increase backward compatibility with Stringprep
   [RFC3454] and precis framework [I-D.ietf-precis-framework].  Because
   in a Stringprep profile which specifies Unicode normalization form KC
   (NFKC) for normalization method, fullwidth/halfwidth characters are
   mapped into its compatible form.  If a precis framework profile
   specified NFKC (which is not recommended), width mapping might not be
   useful.

Is backward compatibility the only reason to specify width mapping?

If so, then it would be good to say that width mapping is appropriate
for technologies that are migrating from stringprep (with NFKC) to
precis, but not for technologies that never had a stringprep profile.

If not, then it would be good to explain why it can be appropriate for
a technology that uses precis (but never used stringprep) to specify
width mapping. For example, perhaps width mapping helps to prevent
violations of the "principle of least user surprise" because users in
language communities with fullwidth and halfwidth characters might not
be able to tell the difference between various widths on common devices.

In my opinion, some discussion of the security implications of width
mapping (e.g., the possibility of more "fase positives") would also be
helpful.

Thanks!

Peter

- -- 
Peter Saint-Andre
https://stpeter.im/

-----BEGIN PGP SIGNATURE-----
Version: GnuPG/MacGPG2 v2.0.18 (Darwin)
Comment: Using GnuPG with Mozilla - http://www.enigmail.net/

iEYEARECAAYFAlBbbxkACgkQNL8k5A2w/vwbdwCfWoKE3UInmTbnBMG4Zbv9gHfr
JTAAoJBXvP/FsphnbmPXxjnYeYKu204f
=i6jZ
-----END PGP SIGNATURE-----
_______________________________________________
precis mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/precis

Reply via email to