Date: Tue, 24 Jan 2006 18:04:27 -0800
   From: Per Bothner <xxxxxx@bothner.com>
   Cc: srfi-83@srfi.schemers.org

   Alan Bawden wrote:
   > Which moves me to wonder if the Scheme Editors are planning on
   > registering the "scheme:" scheme with the IETF and IANA?
   >
   > URI systax is an incredibly ugly thing, as anyone who has ever written
   > a URI parser can tell you -- but there may well be some advantage in
   > using URIs if there is some way to leverage all the existing
   > URI/URL/URN infrastructure.  I.e., if something really useful happens
   > if someone uses "ftp://..." in a Scheme module.

   Be careful to distinguish URIs "identifiers" vs URLs "locators".
   Some URIs, such as namespace URIs in XML, are just identifiers.
   There is no expectation that the URI point to anything you can
   access - it is just supposed to be a unique strings.  Putting it
   in the form of a URI is one way to achieve that.

   Persumably a "scheme://" URI is just that - an identifier.  Thus
   there isn't any need to register "scheme:".

The specification of what it means to be a URI is RFC 3986 ("Uniform
Resource Identifier (URI): Generic Syntax"), which explains that each
scheme needs to be tied to a document that describes that scheme's syntax,
and it refers you to the process for registering new schemes.

So are these things URIs or aren't they?  If they are really URIs, then
Scheme needs to register it's scheme so that we won't be in danger of
collision with other users of URIs.  If these aren't really URIs, then
Scheme doesn't need to be using the baroque URI syntax.

Everybody should be sure to go and read RFC 3986.  If Scheme is going to
use URIs, you should all be sure you understand how they work.