make a necessary distinction between resource deletion and collection deletion. State the client intent on sending DELETE, and ensure APP is consistent with HTTP and WebDAV in that regard.
APP up to 06 is overspecified; it conflates deletion of resources with the DELETE method with collection removal.
remove from "5.3.3 Deleting a Resource",
Note: deleting a member also removes it from all the collections to which it belongs.
and, add this text instead:
Note: deleting a member resource does not necessarily remove it from the collections in which it appears. The intent of DELETE in the Atom Protocol is to delete the resource identified by the Request-URI, not to remove it from one or more collections.
If we need client ability remove members from APP Collections (as opposed to the web), that's a separate matter and requires another Pace. This Pace is here to address overspecification only.
See also: PaceRemoveListTemplate See also: PaceClarifyCollectionAndDeleteMethodByWritingLessInsteadOfMore