Any Ordering Issues
The spec provides only for client-maintained orderings.
Server-maintained orderings would probably be based on property values, and so are equivalent to DASL search with a sort-by element. (A search would probably be less efficient than a PROPFIND with members returned in accordance with a collection ordering.)
What if a server wants to provide server-maintained orderings?
Currently, it canít. The only values for DAV:orderingtype are unordered, custom, and a client-specified semantics. For any collection that is ordered, if the client doesnít specify the position of some collection member that it adds, the server is required to put it at the end of the ordering.
Do we want to change this so that itís possible for a server to provide server-maintained orderings?
We could allow servers to advertise the server-maintained orderings they can provide in OPTIONS. Then if the value of DAV:orderingtype is one of those, the server maintains the ordering and fails any request that contains a Position header for that collection.