from an email from Daniel:
> Hum, currently the URI modules follows 2396, but 3986 is out which
> obsoletes 2396,   http://www.ietf.org/rfc/rfc3986.txt
>   "This document obsoletes [RFC2396], which merged "Uniform Resource
>    Locators" [RFC1738] and "Relative Uniform Resource Locators"
>    [RFC1808] in order to define a single, generic syntax for all URIs.
>
> the uri.c module needs to be updated. Problem is that most XML specs
> reference 2396 normatively ... Evolution of standard is always a hard issue.
> I suggest you open an enhancement request in bugzilla.