URI vs. URI reference for system identifiers

[Bjoern Hoehrmann <derhoermi@gmx.net>]

Hi,

   XML 1.0 Second Edition 4.2.2. reads:

  "[Definition: The SystemLiteral is called the entity's system
   identifier. It is a URI reference (as defined in [IETF RFC 2396],
   updated by [IETF RFC 2732]), meant to be dereferenced to obtain input
   for the XML processor to construct the entity's replacement text.] It
   is an error for a fragment identifier (beginning with a # character)
   to be part of a system identifier."

As per RFC 2396, the difference between an URI and an URI reference is,
that the URI reference allows an additional fragment identifier attached
to the URI. Could someone please enlighten me, why the system identifier
isn't just an URI? To me it's nonsense to use an URI reference and
forbid the only feature it brings.

This was also reported to xml-editor@w3.org, but as usual, I got no
reply on my report...

regards,
-- 
Björn Höhrmann { mailto:bjoern@hoehrmann.de } http://www.bjoernsworld.de
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