Two preferred routes over the North Atlantic Organized Track System (NAT OTS) now require cockpit datalink capability. The ICAO requirement calls for two datalink capabilities, controller-pilot datalink communications (CPDLC) and ADS-C (Contract). Flight departments planning to equip for datalink communications to meet this requirement will have to obtain a letter of authorization from their local FAA FSDO. One of the benefits of equipping with CPDLC and ADS-C will be the ability for ATC to allow tighter separation between compliant traffic over the North Atlantic, including climbs to more efficient altitudes. Gander and Shanwick Oceanic Control Areas have been running a trial of reduced longitudinal separation minimums, and properly equipped aircraft are invited to participate.