Well app:accept is not an element of the feed anyway. It's part of the service document so collection feeds aren't really differentiable from other feed types in that fashion.Please see discussion on best practice for discovering collections [1] for details. We are proposing to formalize this best practice in the hierarchy I-D [2]. I also have a blog post that describes this [3].
RFC 5023 suggests feeds can contain a app:collection element that references the actual collection location and metadata. Looking at the best practices defined in [1], I found the terminology to be rather complicated for what it seemed to me, solely adding new rel values and I'm wondering why this would be more commonly implemented than whatever exists now (rel="service" + embedded app:collection). But that's OT in regards to the current discussion.
- Sylvain [1] http://www.imc.org/atom-protocol/mail-archive/msg11349.html