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Re: Colons in URIs (rfc2396) for Universal Media URNs in URLs

From: Aaron E. Walsh <aaron@mantiscorp.com>
Date: Sat, 19 Aug 2000 18:21:54 -0400
Message-ID: <399F0882.4ED73C3A@mantiscorp.com>
To: URI W3C List <uri@w3.org>
Hi Michael, thanks for your fast reply. I'm glad to hear that you think
we'll be able to use colons in our URLs without escaping them, which in
turn allows us to cleanly embed our URNs into URLs for HTML and other
single-URL and URN unaware apps (Web browsers, in particular!).

Leslie has also suggested that we register the Web3D URN, which I'll do
this month. Do you think it makes sense to include the URN embedded in
URL examples (such as those below), or just the URN syntax/usage in our
registration RFC?

Best regards,
Aaron
-- 
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Aaron E. Walsh  http://www.mantiscorp.com/people/aew/  617.350.7119
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Michael Mealling wrote:
> 
> On Fri, Aug 18, 2000 at 05:07:25PM -0400, Aaron E. Walsh wrote:
> > I wonder if un-escaped colons are legal in the path portion of a URL so
> > long as they're not in the scheme or domain? For example:
> 
> According to 2396 and my personal experience its legal. From the ABNF:
> 
> absoluteURI   = scheme ":" ( hier_part | opaque_part )
> hier_part     = ( net_path | abs_path ) [ "?" query ]
> abs_path      = "/"  path_segments
> path_segments = segment *( "/" segment )
> segment       = *pchar *( ";" param )
> pchar         = unreserved | escaped |
>                       ":" | "@" | "&" | "=" | "+" | "$" | ","
> 
> Which means that pchar says that an unencoded ':' is fine in
> the path segment...
> 
> > http://www.web3dmedia.com/urn:web3d:media:/textures/nature/grass_1.jpg
> > http://www.officetowers.com/urn:web3d:media:/textures/nature/rocks_3.jpg
> 
> Yep. I've seen that used before. The PDI URN space uses it...
> 
> > I ask because our Web3D Universal Media Working Group uses URNs for
> > media referencing, which we'd like to extend to single URL environments
> > such as standard HTML browsers and authoring tools (our use of URNs is
> > based on the VRML97 ISO standard, which supports multiple URLs/URNs).
> > The two URLs above show how we might embed a URN into a URL so that the
> > media can be resolved via http (over the net) by products that don't
> > understand Universal Media (just like a normal URL) while also giving
> > products that understand our system what they need to know in order to
> > fetch the media from the user's local system (the URN identifier
> > "urn:web3d:media:" is the key; this tells Universal Media products that
> > a piece of media is likely be be locally resident and so they'll attempt
> > to resolve it locally first before trying the Web).
> >
> > I chair the Universal Media Working within the Web3D Consortium, and I'd
> > like to extend our media system to URL/URI environments *without*
> > conflicting with standard use of URIs/URLs. If you'd like some
> > background on our work before commenting please feel free to visit our
> > site at:
> >
> >   http://www.web3dmedia.com/UniversalMedia/
> >
> > To see how we deal with URNs, you can read our recommended practice:
> >  http://www.web3dmedia.com/UniversalMedia/course/
> >   see "VRML, URNs and Universal Media Recommended Practice Proposal"
> >
> >
> > Below my signature is a message I recently sent to our group regarding
> > using colons in URLs so that our URNs can be used by a wider audience.
> > I've since read rfc2396 again and would like to know if it's possible to
> > include colons in URLs without escaping them, like these:
> >
> > http://www.web3dmedia.com/urn:web3d:media:/textures/nature/grass_1.jpg
> > http://www.officetowers.com/urn:web3d:media:/textures/nature/rocks_3.jpg
> >
> > Is this legal so long at the colon appears in the path (as above) and
> > not in the scheme or domain?
> 
> >From my reading, yes...
> 
> BTW, now that there is a URN registration process would it be to much
> trouble to have this one registered? It just needs a short RFC on what
> the space is and how its managed. See RFC 2611....
> 
> -MM
> 
> --
> --------------------------------------------------------------------------------
> Michael Mealling        |      Vote Libertarian!       | www.rwhois.net/michael
> Sr. Research Engineer   |   www.ga.lp.org/gwinnett     | ICQ#:         14198821
> Network Solutions       |          www.lp.org          |  michaelm@netsol.com

-- 
Aaron
-- 
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Aaron E. Walsh   http://www.mantiscorp.com/people/aew/   617.350.7119
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Received on Saturday, 19 August 2000 20:15:35 GMT

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