SamRuby: I've been looking at each element in atom:entry from the perspective of Tim Bray's Stamp Out Creativity Now, and creating a number of Paces along the way. The primary changes are to make a number of things which are optional in RSS, required in Atom; and a number of things that are implicit or ambiguous in RSS, explicit in Atom.
This page is intended to show the status of this work in progress.
content (title, summary, content)
PaceContentAsTextOrHtml : limit all such content to text/plain, text/html, and application/xhtml+xml. Eliminate mode attribute (text is escaped, xhtml is inline). At least one of summary and content is required.
PaceLinkAttrDefaults : limit rel values to alternate and related (the two primary use cases in RSS)
person (author, contributor)
PaceIdConstruct : require ids to be immutable over location and time, and compared character by character
date (modified, issued, created)
PaceDateElement: replace all three elements with a single date element that MAY change, MAY be sorted, and MAY be not displayed until the date indicated.
No changes proposed.
PaceIdConstruct: replace language identifying alternate of feed with id of feed. Note: this element is an invention