Re: Is this use of BASE kosher?

Paul Burchard (
Wed, 2 Aug 95 21:26:51 EDT

"Daniel W. Connolly" <>
> The point is that you don't _need_ to retrieve a
> representation of the resource identified by the base
> URL: you've already got it!

Not necessarily. Let's take the specific example that started this
whole discussion. I will phrase it as an HTTP response so that we
can assume we obtained the document as the result of retrieving the
URI shown:

200 OK
URI: <>
Content-type: text/html

<base href="">
<a href="#Printers">Printers</a>
<h3><a name="Printers">Printers</a></h3>

It's true that *without* the <base> tag, the relative URL
"#Printers" would resolve to
"" according to the
rules of RFC 1808. The entity corresponding to the URL
"" would then (luckily!)
already be in front of us, and the agent would merely need to scroll
down to get "".

However, *with* the <base> tag, the relative URL "#Printers"
instead resolves to ""
according to RFC 1808 (please read it). Thus, a correct user agent
must retrieve the entity representing the URL
"" and find *its* "Printers" fragment
-- and we do not already have it in front of us.

This example may seem peculiar, but the rules of RFC 1808 are
designed to keep the following orthogonal:
* the determination of the base URL;
* the process for resolving relative URLs;
* the URL scheme (as long as it obeys the generic-RL syntax).

(Datapoint: OmniWeb for the NeXT resolves these URLs correctly.)

Paul Burchard <>
``I'm still learning how to count backwards from infinity...''