Allow flexbility in how the protocol evolves by removing the requirement that collections must be sorted by their entries' atom:updated value.
The specification to sort all collections by updated is overconstrained
we don't know enough about what will people need to enforce a single sort order on collections
sort by updated might make future sync'ing efforts difficult to achieve
In section 9 Listing Collections, remove
The entries in the returned Atom Feed MUST be ordered by their "atom:updated" property, with the most recently updated entries coming first in the document order. Clients SHOULD be constructed in consideration of the fact that changes which do not alter the entry's atom:updated value will not affect the position of the entry in a collection
Server: deployed implementations can continue to serve collections sorted by updated
Clients: cannot assume that the entries are sorted by their atom:updated values
Future extensions could provide an app:sort containing the Clarkname of the element entries are sorted by. Providing a means for a client to specify the sort order of a collection by using an entry tuple or URI templates is another possible extension (this would be a primitive query langauge).