Re: An Anchor attribute question:

Daniel W. Connolly (connolly@hal.com)
Thu, 02 Jun 1994 10:40:14 -0500

In message <199406021522.AA19445@oit.gatech.edu>, Michael Mealling writes:
>Daniel W. Connolly said this:
>> Actually, now that I think about it, If you're not going to include
>> a redundant URL, why don't you just write:
>>
>> <A HREF="URN:IANA:IETF:rfc/822"> ...</a>
>>
>> ???
>
>This would work also. I would like to be able to make this distinction
>in HTML though. Simply to keep in the spirit. There also seems to be
>something in HTParse.c that is causing that example URN to be invalid
>since HTParse.c: scan() function makes the assumption (which may be
>a correct one according to the current URL spec) that no other colon
>should exist beyond the first one. This is causing HTParse() to turn
>the above into "URN:rfc/822" by basically looking at the first colon
>READING BACKWARDS.
>
>Is this correct?

Well... it depends on how you want to look at it. The URI working
group's definition of URL is
scheme:anything

The WWW definition of URI (the contents of the HREF attribute) is:
scheme://hostport/dir1/dir2;param=value?search#fragment
where all the parts are optional, but only certain combinations
make sense. (See
http://info.cern.ch/hypertext/WWW/Addressing/URL/URI_Overview.html
for details)

So any WWW URI is an IETF URL, but the converse isn't true.
HTParse.c assumes you're handing it a URI.

Now if you define the syntax of URN to be:
URN:anything
then any URN is a URL, but it's not a URI.

It would make more sense to me to define the syntax of URNs
such thaty they are also URIs. So in stead of:

HREF="URN:IANA:IETF:rfc/822"
you would write:
HREF="URN://IETF.IANA/rfc/822"

It's just an expedient measure to hasten deployment. The syntaxes
have equivalent expressive power.

Dan