[vox-tech] one of the most pernicious spams i've ever seen.

Micah J. Cowan vox-tech@lists.lugod.org
Thu, 25 Sep 2003 14:08:06 -0700


On Thu, Sep 25, 2003 at 11:07:39AM -0700, Michael J Wenk wrote:
> On Thu, Sep 25, 2003 at 10:57:25AM -0700, Mark K. Kim wrote:
> > I think what you've described is the URI.  URL is supposed to be a subset
> > of URI, whatever that means.  I personally don't care but I wouldn't mind
> > knowing what that means if anyone else knows.
> 
> 
> I referred to an RFC that desribes URIs, which I did at one time
> read(several years ago), or perhaps I read it in a book, I forget.  In
> any event, a URI is the identifier portion of the URL.  It tells you
> what resource you are trying to get, but not how to get it.  In simpler
> terms it would be everything to the right of the :// in URL.  I suggest
> you check the RFC I referenced, as I may be off a bit. 

Absolutely untrue, actually. As Mark said, URL is a subset of URI, not
vice versa. No part of a URL is a URI; all of a URL is always a URI. A
URI (Universal Resource Identifier) is a superset of URL (Universal
Resource Identifier), including one other type of identifier (which
can sometimes overlap URL), URN (Universal Resource Name). URNs are
beasts which refer to a resource by identifying them uniquely, not
(necessarily) specifying where they exist. There are several schemes
in existence, but most of them have yet to be put into practice. One
noticeable exception is "persistent URLs", which is a URL that is
expected to persist over time.

The stuff to the left of the first ":" in a URI (URNs have 'em too) is called
the "scheme".

HTH,
Micah