Several vessels are at an anchorage. You wish to communicate with the vessel bearing 046°T from you but do not know the vessels call letters. Which flag hoist should NOT be used to establish communications?

Correct Answer: Option A — RQ A046

Signal "RQ A046" is invalid because the designator requires specific call signs rather than a relative bearing alone when attempting to establish contact with an unknown vessel at an anchorage using standard code protocols.