The XA and XU divisions have compiled a standard operating procedure document for North Atlantic control. This document covers procedures for both Gander and Shanwick Oceanic FIRs.
Before attempting to connect to any oceanic position all controllers, regardless of division of origin, must complete oceanic training which is offered by the Shanwick/Gander FIR. Upon completion of this training the controller is rated to work both Gander and Shanwick positions.
It is important to understand that staff of either division have full jurisdiction over both FIRs, and their instructions should be complied with.