When sending Armed Forces Air Letters out of Canada, foreign military forces serving in Canada must use form number 43-074-078 with domestic Lettermail postage affixed. A sender must indicate the following details in the upper left-hand corner, under their name and address:

• Number, rank, and name
• “COMMONWEALTH FORCES” or “NATO FORCES”/Country
• Address in Canada

For example:

16779 MAJOR J. SMITH
NATO FORCES/ENGLAND
RR1
OROMOCTO NB  E2V 2G2