Observation [200]–201
Observation of target and fire [428]–429
OBSTACLES:
Abatis[1176]
Against cavalry[1180]
Automatic alarms[1192]
Barricades[1185]
Cheveaux de frise[1179]; [1189]
Fraise[1178]
Guarding obstacles[1190]
In front of outguards[1187]
Inundations[1186]
Kinds[1176]
Lessons from European War[1188]
Listening posts[1191]
Location[1175]
Military pits[1184]
Necessity for[1174]
Object[1173]
Palisade[1177]
Search lights[1193]
Trous de loup[1184]
Wire entanglements[1181]; [1182]; [1188]
Wire fence[1183]
Obstacles located by Major [358]
Occupation of ground [1426]
Offensive necessary for decisive results [367]
Office, how to enter [1527]
Officer of the Day [1593]
OFFICERS:
Posts of[71]
To be true leaders[377]
To comply with spirit of orders[377]