Instead of putting app:collection elements in a feed document, create a new link relation that points to the <del>introspection</del> service document.
Drop the last sentence of Section 7.2.3.
Add Section 10.3
10.3 The "service" Link Relation The Atom Protocol adds the value "service" to the Atom Registry of Link Relations (see section 7.1 of [RFC4287]). The value of "service" specifies that the value of the href attribute is the IRI of a Service Document. An atom:entry can contain zero or more "service" link relations.