Re: URN single or multiplevariants

Tony Sanders <>
Message-id: <9309241645.AA01053@austin.BSDI.COM>
Subject: Re: URN single or multiplevariants 
In-Reply-To: Your message of Fri, 24 Sep 93 08:24:38 +0700.
Organization: Berkeley Software Design, Inc.
Date: Fri, 24 Sep 1993 11:45:38 -0500
From: Tony Sanders <>
So the returned URI: lists the attributes that vary for a given URN.
Then it is up to the client/browser to specify which of those it
wishes to constrain (e.g., in HTTP using Accept: fields).

So for an image it might be:
    URI: img-urn1 vary="content-type,class,depth,width,height,xdpi,ydpi"
And audio might be:
    URI: au-urn2 vary="srates,widths"

Then the request might be:
GET img-urn1 HTTP/1.0
Accept: image/gif,class=color,depth=8,width=1024,height=768,xdpi=85,ydpi=85
X-Comment: This server probably has a postscript image since it
X-Comment: says it can convert it to just about anything for us.

[FYI: these examples come from the information in]

> Does that make it any clearer what I meant?
If my summary above is correct then I think it's crystal clear.