"ATOM FEED DOCUMENTS

At any point where an ATOM document of type Feed is sent or returned, it must be a valid atom Feed document and conform to the guidelines below:
...
d. Id will be URI of the resource
..."

I don't see how the URI of the resouce can be a valid Atom ID, unless the URI can never change.

Keep in mind that

"The "atom:id" element conveys a permanent, universally unique identifier for an entry or feed." – <http://greenbytes.de/tech/webdav/rfc4287.html#rfc.section.4.2.6>