> > - don't ever let the client tell the server > - include a list of acceptable controls with each operation request, > assuming that the server is really stupid, and > can't remember the list from one operation to the next. > - define a new extended operation that allows the client to submit a > list of acceptable controls
there is the obvious alternative missing from your list, which we have now, ie. the client specifies which control it wants on each individual operation :-)