We are really just providing a binding sharing operation. It guarantees to bind to the same resource as another URL binds to. We are providing protocol access to the URL binding operation. LOCK affects a particular binding and a resource. Clients could still remove other bindings and introduce new binding while the lock is in force.
Some servers do case folding.
How to model that. Maybe best to be silent on this. This seems completely natural if the reference is just a URL binding, instead of seeming puzzling. A direct reference creates a binding. Jim W thinks yes.