[idn] Comment on draft-hoffman-stringprep-04.txt

[Simon Josefsson <jas@extundo.com>]

Quoting section 1.2 "Each profile MUST state the character repertoire
on which the profile will operate. Appendix A lists the Unicode
repertoires that can be selected."

Quoting section 7 "Using two different policies for where unassigned
code points can appear removes the need for versioning in protocols
that use stringprep profiles. This is very useful since it makes the
overall processing simpler and does not impose a "protocol" to handle
versioning. It is expected that the ISO/IEC 10646 and Unicode
repertoires will be updated fairly frequently; at the time that this
document is being written, it has happened approximately once a
year. Each time a new version of a repertoire appears, a new version
of a profile MAY be created. Some end users will want to use the new
code points as soon as they are defined."

In section 7, one is lead to believe that profiles can chose to adopt
more recent versions of the Unicode standard, but this cannot happen
until stringprep itself is updated, by the MUST in section 1.2.
Suggested new text in section 7:

.. Each time a new version of a repertoire is offered by an updated
version of this specification, a new version of a profile MAY be
created. ...