URI
Notation
623.1/.7
Caption
Land-based military engineering. Artillery
Broader class
623  Military engineering
Narrower classes
623.1/.3Field engineering. Fortifications. Defence works
623.4Armaments. Ordnance. Arms. Weapons. Guns. Artillery. Small arms. Side arms. Armoured and other service vehicles. Ammunition and war gases. Guided missiles and rockets
623.5Ballistics. Gunnery. Theoretical and experimental problems
623.6Field engineering equipment and operations. Lines of communication. Radar countermeasures. Military topography
623.7Military and naval aviation. Air defence