Chapter 4, section 2 waxes eloquent on radio communications phraseology and techniques. It's true that the AIM is not regulatory, but rather advisory in nature. Still, there's solid logic to most of what you read within its pages, and this section is a case in point. Take how you are advised to make your initial contact (or "call up") with a new controller. Whenever you are about to chat with someone new on the other end of the microphone line, the AIM advises you start your transmission with the name of the facility you're calling, as in: "Boston Center…" or "Albuquerque Departure…" Next, give your full aircraft call sign as filed in your flight plan (could be different from your tail number, for example, if you're on a mercy flight). Next, if you're on the ground at an airport, tell the controller where you are on the field. If your message is short, now's the time to spit it out. If not, a few words that will indicate what you're looking for would help at this stage, such as: "Requesting VFR advisories" or, if getting close to the destination with lots of altitude underneath you: "Looking for lower." Finally, the AIM actually says you can throw in, "Over" at the close of your transmission. It means you're expecting a reply, as in "over to you" or "the ball's in your court."