- From: Mark Nottingham <mnot@mnot.net>
- Date: Wed, 10 Dec 2008 20:51:07 +1100
- To: Julian Reschke <julian.reschke@gmx.de>
- Cc: "Roy T. Fielding" <fielding@gbiv.com>, HTTP Working Group <ietf-http-wg@w3.org>
I though I had it, but I don't; Roy's explanation made sense, but his interpretation of HTML2 links -- AIUI -- contradicts the example in HTML2's REV definition. Roy? On 10/12/2008, at 8:28 PM, Julian Reschke wrote: > > Mark Nottingham wrote: >> ... >> <t>HTML4 also has a "rev" parameter for links that allows a >> link's relation to be reversed. The Link header >> has a "rev" parameter to allow the expression of these links >> in HTTP headers, but its use is not encouraged, >> due to the confusion this mechanism causes as well as >> conflicting interpretations among HTML versions.</t> >> ... > > OK, it seems I'm missing something here. Could somebody explain to > me, what the conflicting interpretations are, and which we prefer > (and why?)? > > HTML2 (<http://tools.ietf.org/html/rfc1866#section-5.7.3>): > > REL > The REL attribute gives the relationship(s) described by > the hyperlink. The value is a whitespace separated list > of relationship names. The semantics of link > relationships are not specified in this document. > > REV > same as the REL attribute, but the semantics of the > relationship are in the reverse direction. A link from A > to B with REL="X" expresses the same relationship as a > link from B to A with REV="X". An anchor may have both > REL and REV attributes. > > HTML4 (<http://www.w3.org/TR/html4/struct/links.html#rev-link>): > > 12.3.1 Forward and reverse links > > The rel and rev attributes play complementary roles -- the rel > attribute specifies a forward link and the rev attribute specifies a > reverse link. > > Consider two documents A and B. > > Document A: <LINK href="docB" rel="foo"> > > Has exactly the same meaning as: > > Document B: <LINK href="docA" rev="foo"> > > Both attributes may be specified simultaneously. > > > > Best regards, Julian > -- Mark Nottingham http://www.mnot.net/
Received on Wednesday, 10 December 2008 09:51:47 UTC