query on iregname conversion

I'm still working on a draft that turns the MAY into a MUST for
ireg-name processing; it winds up rewriting a lot of the
document because it puts parsing before percent-encoding.

I'd rather wait to discuss this until I have a draft ready
(had hoped to finish yesterday).

One section I've stumbled on is:


   Systems accepting IRIs MAY convert the ireg-name component of an IRI
   as follows (before step 2 above) for schemes known to use domain
   names in ireg-name, if the scheme definition does not allow percent-
   encoding for ireg-name: Replace the ireg-name part of the IRI by the
   part converted using the ToASCII operation specified in Section 4.1
   of [RFC3490] on each dot-separated label, and by using U+002E (FULL
   STOP) as a label separator, with the flag UseSTD3ASCIIRules set to
   TRUE, and with the flag AllowUnassigned set to FALSE for creating
   IRIs and set to TRUE otherwise.  The ToASCII operation may fail, but
   this would mean that the IRI cannot be resolved.  This conversion
   SHOULD be used when the goal is to maximize interoperability with
   legacy URI resolvers.  For example, the IRI
   "http://résumé.example.org"
   may be converted to
   "http://xn--rsum-bpad.example.org"
   instead of
   "http://r%C3%A9sum%C3%A9.example.org".


Can someone explain the AllowedUnassigned set to FALSE for "creating
IRIs"?  This is in the middle of the algorithm for converting IRIs
(which is turning into converting 'parsed IRI components' into
'parsed URI components'), but what is the applicability of 
'creating IRIs' when doing this mapping anyway?

Larry

Received on Wednesday, 2 September 2009 17:12:35 UTC