Should be clearer that clients *are* the controlling parties

[burnburn]

On a straight read-through of the doc, by the time I had reached section 5.1.1 I had seen several sentences like this one there: "The Rayo server is responsible for keeping track of valid clients, routing calls to the correct potential controlling parties, ..." that make it sound as if valid clients and potential controlling parties are not the same thing. Are they actually different, or is the latter just a subset of the former?