оперативна директива
dead letter-box
letter bomb (parcel bomb, mail bomb, postal bomb etc)
letter order
letter of agreement
letter of commendation
action letter
immediate action letter
call letter
speed letter
recruitment letter
command letter
circumstantial letter
commendatory letter
Mike (letter M in the phonetic alphabet)
Air Force letter
personnel news letter
letter of censure
Chairman of the Joint Chiefs of Staff Instruction (CJCSI)
Department of Defense Instruction (DODI)
exercise instruction
formal instruction
package instruction
preliminary rifle instruction (PRI)
signal operation instruction
tactical instruction
combat instruction
instruction pamphlet / instructional pamphlet
academic classes that provide instruction on counterintelligence
driver's instruction
flight instruction
instruction plate
maintenance instruction