Re: Hyperlinks: (1. Background)

Per Tim's reasonable suggestion, I am breaking up my commentary message
into topical email-bites.

At 8:19 PM 12/19/96, Tim Bray wrote:
>Minimum Progress Required to Declare Victory
>1. Background
>The Web is the largest working hypermedia instance.  It supports one
>widely-used form of hyperlink, the <A> or Anchor element.  These links are
>unidirectional and [this is a basic design principle of the web] specify
>basically nothing about their target except its location.  The links carry no
>typing or role information, beyond the unconstrained text that may be found
>between the <A> and </A> tags.  HTML offers another hyperlink facility, the
>LINK header element, but it is not widely used.
>Web links support a variety of behaviors, governed by the interaction of the
>"scheme" part of the URL (http:, file:, ftp:, mailto:) and the logic in the
>"User Agent" (typically a browser).  It might be argued that there are really
>a smaller number of behaviors (a) retrieve and display, (b) retrieve and save,
>(c) send mail; but the number of behaviors exceeds one.

I would say that the behaviors are more determined by browser: for instance
(at least some versions of) Netscape would display ftp files that contained
HTML, rather than downloading. And nowadays all browsers can change their
behavior based on the content-type (or extension) of the file (regardless
of the protocol used to fetch it). My point is only to agree that we need
an <a> tag, but that the semantics of what it does are pretty inconsistent
and should not overly constrain us. Basically browsers currently guess what
was intended, since there is no link-type information at all.

   -- David

I am not a number. I am an undefined character.
David Durand              dgd@cs.bu.edu  \  david@dynamicDiagrams.com
Boston University Computer Science        \  Sr. Analyst
http://www.cs.bu.edu/students/grads/dgd/   \  Dynamic Diagrams
--------------------------------------------\  http://dynamicDiagrams.com/
MAPA: mapping for the WWW                    \__________________________