W3C home > Mailing lists > Public > www-rdf-interest@w3.org > August 2001

Re: URIs vs. URNs vs. URLs

From: Roy T. Fielding <fielding@ebuilt.com>
Date: Fri, 3 Aug 2001 18:29:33 -0700
To: "Sean B. Palmer" <sean@mysterylights.com>
Cc: uri@w3.org, www-rdf-interest@w3.org
Message-ID: <20010803182933.F1122@waka.ebuilt.net>
> * However, although persistence as a "quality of service" is therefore
> a qualitative thing, it is evident that in practise there is a
> difference between URLs and URNs in general in that the persistence of
> URNs is generally better than that of URLs. This is not quantitative,
> and not a rule

Ummm, where do you get that "evident" from?  In my experience, a typical
bookmarked URL will outlast a URN.  The reason is because unimplemented
persistent naming mechanisms go in and out of fashion.  A name (ANY NAME)
will never be persistent until someone makes enough good use of that name
to justify the cost of making it persist.  Persistence is not, and never has
been, a function of the syntax used to create the name.

If you want persistent names, ask a library to create one -- the syntax
only determines how often the name will be used.  Making it a URN only
reduces the name's scope of use.

....Roy
Received on Friday, 3 August 2001 21:33:36 GMT

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