For Draft -09
Having a way of indicating the date the entry was last modified is a good optimization to avoid having to HEAD each individual member URI to get the Last-Modified header.
The element is also useful for detecting minor changes that do not impact the value of atom:updated.
8.# The "atom:modified" Element The "atom:modified" element is a Date construct as defined by [RFC4287] whose value indicates the most recent instant in time when an entry was modified in any way. Atom entry elements MUST contain one "atom:modified" element. atomModified = element atom:modified ( atomDateConstruct ) Publishers MUST change the value of this element every time a collection member resource has been updated, or an associated Media Resource has been modified.
Adds a new mandatory element to every element in a collection feed.
<entry xmlns="http://www.w3.org/2005/Atom" xmlns:app="..."> <id>urn:lsid:example.org:entries:1</id> <updated>2006-07-11T12:12:12Z</updated> <modified>2006-07-11T12:13:13Z<modified> ... </entry>