observer identification

observer-target distance

obstruction

occupation of position

offensive mine countermeasures

officer conducting the exercise

officer conducting the serial

officer in tactical command

officer scheduling the exercise

offset distance

offset point

offset post

on call

on-call target

O-O line

operation

operational aircraft cross-servicing requirement

operational chain of command

operational characteristics

operational command

operational control

operational interchangeability

operational level of war

operational reserve

operational stocks

operation order

operation plan

operations security

opposing forces

opposing forces commander

organic

other forces for NATO

over

overlap

overlap tell

overrun control

overshoot