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PaceAllowDuplicateIdsWithModified


Abstract

This proposal allows multiple atom:entry elements with the same atom:id value in the same Atom Feed Document.

This proposal is based on PaceAllowDuplicateIDs. The addition of atom:modified means that it is not necessary to require multiple revisions of an entry to have unique atom:updated values, because atom:modified can be used to more reliably identify the latest revision of an entry.

Status

Draft

Author: DavidPowell

Rationale

PaceAllowDuplicateIDs requires entries with duplicate ids in a feed to have unique values of atom:updated. This is currently necessary so that a processor can identify the latest revision of an entry. But it is not possible for a re-publisher to emit unique values of atom:updated for multiple revisions of an entry unless they drop revisions with the same date. Just because an author didnít assert that an update was subjectively significant, doesnít imply that a re-publisher or archiver will not want to emit it in a feed.

atom:updated doesnít reliably differentiate different multiple revisions of an entry; the value of atom:updated is only updated when the author wishes to indicate a significant change, but archivers and intermediaries may wish to emit all revisions of entries. Atom requires a Date construct that can be reliably used to distinguish multiple revisions of an entry and select the latest.

Proposal

in format-08:

1. Remove the last bullet point in 4.1.1

2. Add the following paragraph, either to atom:entry or atom:feed, at the editors' discretion.

If multiple atom:entry elements with the same atom:id value appear in
an Atom Feed document, they represent multiple revisions of the same
entry; software MAY choose to display all of them or some subset of
them.  One typical behavior would be to display only the entry with
the latest atom:modified timestamp.

Impacts

Improves usability of Atom as a feed archive format. Enables Atom feeds to provide multiple timestamped revisions of entry descriptions.

Requires PaceDateModified2 to be accepted.

Notes

This proposal is based on [WWW]draft-ietf-atompub-format-08.txt.


CategoryProposals