According to ICAO DOC 4444 "PANS ATM" strategic lateral offsets shall only be authorized in en-route oceanic or remote continental airspace. The routes or airspace where application of strategic lateral offsets is authorized, and the procedures to be followed by pilots, shall be promulgated in aeronautical information publications
AIP(s) by the concerned State(s) or, as applicable, by the authorised ANSP(s).
Furthermore, PANS ATM specifies that the strategic lateral offset shall be established parallel to the designated ATS route at a distance of 1.85 km (1 NM) or 3.7 km (2 NM) to the
RIGHT of the centre line relative to the direction of flight. These two "track" options become available in addition to the track centreline, not instead of it. All ATC route clearances are made without reference to the lateral offset option and flight crew do not need to obtain permission from ATC to use these offset tracks or advise ATC of their decision to do so. If there are areas of radar surveillance, within trans-oceanic or remote continental areas, designated for lateral offset procedures, then it is expected that aircraft will be allowed to initiate or continue offset tracking in exactly the same way as the rest of the designated area.