User-Agent (Was: Re: Microsoft IE ...)

BearHeart writes:

: . . .
:    Their making a configurable option for the user to put in whatever 
: string they want is a mockery of the system and of all the efforts 
: of this volunteer group. 
: . . .

I agree that such an option should be not be placed in a
shrink-wrapped product.  I do not view gnu-emacs-w3 as shrink-wrapped.
And I am reluctant to endorse the criticism here since the option was
an effort to help users get behind doors locked by servers (and in most
cases not intended to be locked by the information providers) that should
not have been locked.

: . . .
:    But all I've got today is User-Agent and Accept. And "Accept" tells 
: me nothing about what the client does with Tables, or Multi-Block 
: GIFs, or Server-Push (multipart/x-mixed-replace), etc., etc., etc.  
: . . .

About "User-Agent": What is the user-agent?  Is it the fetcher for
http-protocol or is it the "text/html" viewer?  And is
content-negotiation supposed to furnish information about what the
user-configured handler for the type "multipart/x-mixed-replace" does?
(That would be a tall order.)

About what the client does with Tables:  HTML is an implementation of
Standard Generalized Markup Language (SGML), and HTML is specified by
something called a DTD.  (Let's bypass version questions.)  Under the
rules nobody is permitted to look beyond the DTD for the meaning of
"table".

The SGML idea is that the DTD is written to make provision for mark-up
in an abstract structural way rather than in a format-specific way.
That makes provision for many, many possibilities that we tend to
forget when we are using wonderful shrink-wrapped browsers.  (But even
those of us who like these browsers, self-included, sometimes want to
use other things.)  A very down-to-Earth example: I may like what the
server, based on User-Agent, sends my browser for screen rendition.
But if that shipment is insufficiently structural, it might look awful
when I pipe it through "my-html-to-ps".  (If my browser is
shrink-wrapped, you say, I could print from my browser; but, oh, by
the way, I need to change my fontsize first.)

(The "stylesheet" mechanism is supposed to be available for
presentation specificity, but I have not looked into it, and I don't
see it out there yet.)

: . . .
:    You're implying that for it to be successful it must handle 
: all variations as individual cases. That's not practicable. In 
: theory, Yes it can be done; in practice, It's more work than value. 
: I think you know that, and that's why you're supporting the efforts 
: of content-negotiation in HTTP/1.1--and I agree with you. But it's 
: no excuse for breaking what's working today. 
: . . .
: | BearHeart / Bill Weinman | BearHeart@bearnet.com | http://www.bearnet.com/ 

A lot is working today, but unfortunately not everything is working.
I vote for making the extra effort.  (I hate changing fontsize to
print.)

                                   -- Bill
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William F. Hammond                   Dept. of Mathematics & Statistics
518-442-4625                                  The University at Albany
hammond@math.albany.edu                      Albany, NY 12222 (U.S.A.)
http://math.albany.edu:8000/~hammond/                FAX: 518-442-4731
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Received on Saturday, 27 January 1996 16:03:34 UTC