As a USAF pilot, we are told to ask for Radar Advisory Service in Eastern Radar (military radar) because Eastern Radar airspace is uncontrolled and Advisory Service is more that Radar Information and Radar Control is not available. Information provides just that even in cloud, "Traffic 12 o'clock and 6 miles altitude unknown"; Advisory Service would provide an avoidance vector. Civil Aircraft should have Radar Control on civil radar.
The USAF has had some close calls when US pilots did not understand the distinction and assumed the controller was providing separation. Should not be civil problem, but ex-USAF guys are in the habit of asking for Advisory Service. Most still don't get it.