From a pilot point of view, I use the term 'radar heading' when instructed to change frequency and report that heading to the new controller. On the new freq, I say '........on radar heading XXX'. I just make sure the new controller knows that I am on a 'radar controlled heading' and not on a heading avoiding CBs (or whatever other reason there may be) Same token, I would say '........on heading XXX to avoid (build ups)' when avoiding build ups. Once a while some airplanes may be avoiding build ups and some may be on a controller assigned heading in the same sector. Since I am not always quite sure if the new controller knows what heading I am on, I just tell him. Imho, itīs just one more word and everyone is in the picture. Or do you, as controller, feel annoyed? Well, just my 2p.