ISSUE-628: Specification of anchor in HTML/RDF vs HTTP is inconsistent


Specification of anchor in HTML/RDF vs HTTP is inconsistent

Accessing and Querying Provenance
Raised by:
Graham Klyne
Opened on:
Raised by Stian in, as part of comment number 24:

I don't like the approach here with the anchors disconnected from the
hasProvenance - specially not as it is not consistent with the
approach of 3.1. I would have preferred the two approaches to be
equivalent. I now can't construct the Link headers of 3.1 based on the
HTML in 3.2 or the RDF in 3.3. Although I don't particularly like it,
I might recommend changing 3.1 to also have a separate 'hasAnchor'
relation, to make it consistent. (Also it would allow the off-spec
use of hasAnchor without provenance links).

I don't particularly like it either. But we're constrained by use of existing features. We've been over this is previous iterations, and this is what we settled on - the inconsistency was deemed preferable to gratuitous reinvention. In practice I think it will be less of an issue that may at first appear, as I don't see having multiple provenance links *and* anchors as being a common requirement.

We do indeed have a separate hasAnchor relation (it's also used in the RDF representation as well as the HTML), but it's not recommended for use with HTTP.

I'm raising this as an issue so we can ensure there's group consensus, or at least acceptance, for this approach.
Related Actions Items:
No related actions
Related emails:
  1. PROV-AQ issues pending review (from on 2013-03-11)
  2. PROV-AQ responses to Stian's review (part 1) (from on 2013-03-11)
  3. PROV-AQ responses to Luc's review (from on 2013-03-11)
  4. PROV-ISSUE-628 (prov-anchor-inconsistency): Specification of anchor in HTML/RDF vs HTTP is inconsistent [Accessing and Querying Provenance] (from on 2013-02-21)

Related notes:

Proposing no further change.

Graham Klyne, 7 Mar 2013, 15:15:32

Added note in section 3 to acknowledge this, but no substantive change.

The mechanisms used with HTTP and HTML/RDF are slightly inconsistent in their approach to specifying target-URI values. In HTTP Link: headers, an optional anchor= parameter may be supplied for each such header. In HTML and RDF, separate #has_anchor relations are defined. It was felt that avoiding reinvention of existing mechanisms was more important than being completely consistent. If anchors are processed as described in section 1.3 Interpreting provenance records (3rd paragraph), observable behaviour across all approaches should be consistent.

Graham Klyne, 25 Mar 2013, 15:49:17

Display change log ATOM feed

Chair, Staff Contact
Tracker: documentation, (configuration for this group), originally developed by Dean Jackson, is developed and maintained by the Systems Team <>.
$Id: 628.html,v 1.1 2013-06-20 07:37:57 vivien Exp $