options, not nesting?

Larry Masinter (masinter@parc.xerox.com)
Wed, 27 Oct 1993 19:04:17 PDT 

To: uri@bunyip.com

Subject: options, not nesting?

From: Larry Masinter <masinter@parc.xerox.com>

Message-Id: <93Oct27.190431pdt.2795@golden.parc.xerox.com>

Date: 	Wed, 27 Oct 1993 19:04:17 PDT

Rather than making URNs and URLs and URCs and URMs all different
things, one of which contains the other all nested, how about just
allowing various information to be optional?

A resource reference contains

Optionally:
any number of:
resource location (protocol, hostname, port, path)
resource datatype (MIME type and optionally version information
for those resource locations that are not,
self-typing)
Optionally:
resource name

Optionally:
author, keywords, title, price, and other kinds of external
meta-information.

Of course, if you leave everything out, what you have is pretty
useless. I can easily imagine including both a name and a location,
though.

Rather than trying to categorize everything and getting into confusion
about which things are names, which are locations, etc., make the
various things just options.

Opinions?