[AsbjornUlsberg] The specification does not specify that atom:id is a required child node of atom:entry. This pace seeks to change the specification text so atom:id is required.
atom:id should be a required child node of atom:entry.
Change the text in section 4.13.5 to:
4.13.5 "atom:id" Element
The "atom:id" element's content conveys a permanent, globally unique identifier for the entry. It MUST NOT change over time, even if other representations of the entry (such as a web representation pointed to by the entry's atom:link element) are relocated. If the same entry is syndicated in two atom:feeds published by the same entity, the entry's atom:id MUST be the same in both feeds. atom:entry MUST contain an atom:id element, but MUST NOT contain more than one. The content of this element, when present, MUST be a URI.
atom:id can't be an optional child node of atom:entry anymore.