Staff Duties in the Field, 1949. Appendix E. Air Reconnaissance Code. WO 8457 - Staff Duties in the Field, 1949. Appendix F. Vehicle Unit Signs … Mortier van 15 cm. no. 396 Signal Order Records en Reports. FM 11-16. Signal Support Compagny. FM 11-117 Physical Training. FM 21-20 60 mm. Mortar M2. FM 23-85 60 mm. Mortar M19. FM 23-85 81 mm. Mortar M1. FM 23-90 Chemical Mortar 4.2 inch. FM 23-92 Signal Orders Records and Reports. FM 24-16 Signal Orders Records and Reports. FM 24-16 Motor Transport. FM 25-10