FM 101-5-1
Operational Terms and Graphics

Chapter 1


H - The symbol for Levinstein mustard, a blister agent. See FM 3-9.

habitual association - The close and continuous relationship established between support elements and the combat units they support or between combat units that frequently are cross-attached to ensure a mutual understanding of operating procedures and techniques and to increase overall responsiveness.

handover line (JP 1-02, NATO) - A control feature preferably following easily defined terrain features, at which responsibility for the conduct of combat operations is passed from one force to another. (Army) - 1. The handover line applies to other functions besides combat, such as intelligence, electronic warfare, and information warfare. 2. The action is complete when the receiving commander acknowledges assumption of control authority. (See also phase line (PL).) See FMs 1-111, 7-10, 7-20, 7-30, 17-95, 71-100, 71-123, 100-5, and 100-15.

hang fire (JP 1-02, NATO) - An undesired delay in the functioning of a firing system. (Army) - An undesired delay in the functioning of the primer or initiator part of a round of ammunition. See FMs 6-20 series, 7-91, 17-12, and 23-1.

harassing fire (JP 1-02, NATO) - Fire designed to disturb the rest of the enemy troops, to curtail movement, and, by threat of losses, to lower morale. (See also fire and fire support.) See FM 6-20 series.

hasty attack (JP 1-02, NATO) - In land operations, an attack in which preparation time is traded for speed in order to exploit an opportunity. (See also assault, attack, deliberate attack, and movement to contact.) See FMs 1-111, 1-112, 1-116, 7-7, 7-8, 7-10, 7-20, 7-30, 17-95, 71-100, 71-123, 100-5, and 100-15.

hasty crossing (JP 1-02, NATO) - The crossing of an inland water obstacle using crossing means at hand or those readily available, and made without pausing to make elaborate preparations. (See also bridgehead and deliberate crossing.) See FMs 7-7, 7-20, 7-30, 17-95, 71-100, 71-123, 90-13, 100-5, and 100-15.

hasty defense (JP 1-02, NATO) - A defense normally organized while in contact with the enemy or when contact is imminent and time available for the organization is limited. It is characterized by improvement of the natural defensive strength of the terrain by utilization of foxholes, emplacements, and obstacles. (See also defend, deliberate defense, emplacement, and obstacle.) See FMs 7-7, 7-8, 7-10, 7-20, 7-30, 17-15, 17-95, 71-100, 71-123, 100-5, and 100-15.

hasty smoke - Smoke operations characterized by minimal planning and short duration to immediately counter enemy action. See FM 3-100.

hazard - Any real or potential condition that can cause injury, illness, or death of personnel, or damage to or loss of equipment or property.

hazardous material - Any substance which has a human health hazard associated with it. Special storage, use, handling, and shipment safety procedures and protocols must be followed to help protect against accidental human exposure. Hazardous materials are specifically identified under federal law.

hazardous substance - Materials specifically listed under federal regulations for which the spilling of certain quantities requires immediate reporting to federal agencies.

hazardous waste - A solid waste which is either listed as such in federal law or exhibits any of the four hazardous characteristics - ignitability,corrosivity, reactivity, or toxicity.

hazardous waste accumulation site - A specially designated site for the temporary collection of hazardous waste where no container may remain on site for more than 90 days. The site, and containers within it, must be properly markedand certain safety and management procedures apply. There is no limitation on the quantity of wastes which may be kept on site.

haze (smoke) - A light concentration of smoke placed over friendly areas to restrict accurate enemy observation and fire. A smoke haze is not dense enough to disrupt friendly operations. See FM 3-50.

HD - The symbol for distilled Levinstein mustard, a blister agent. See FM 3-9.

heavy drop (HD) (JP 1-02) - A system of delivery of heavy supplies and equipment by parachute. See FM 10-1.

height of burst (HOB) (JP 1-02, NATO) - The vertical distance from the Earth's surface or target to the point of burst. (See also desired ground zero (DGZ) and ground zero (GZ).) See FM 100-30.

herbicide (JP 1-02) - A chemical compound that will kill or damage plants. (Army) - The term includes defoliants, desiccants, plant-growth regulators, and soil sterilants. See FMs 3-9 and 3-100.

herringbone - An arrangement of vehicles at left and right angles to the line of march used to establish security during an unscheduled halt. See FMs 7-7, 17-15, and 55-2.

H-hour (JP 1-02) - The specific hour on D-day at which a particular operation commences. (Army) - It may be the commencement of hostilities; the hour at which an operation plan is executed or is to be executed (as distinguished from the hour the order is issued); or the hour that the operation phase is implemented. The highest command or headquarters coordinating planning specifies the exact meaning of H-hour within the above definition. When several operations or phases of an operation are being conducted in the same area on D-day and confusion may arise over the use of the same hour designation, the letters F, L, S, W, and Y may be used. When this is done, the letters used and their meaning must be stated in the plan or order. Reference to hours preceding or following H-hour will be referred to by using a plus or minus sign and an Arabic numeral following the letter H. For example: H-3 is 3 hours prior to H-hour; H+7 is 7 hours after H-hour. If a time element other than hours is expressed, it must be spelled out (such as H+30 minutes). (See also D-day.)

hide - The positioning of a vehicle, individual, or unit so that no part is exposed to observation or direct fire. (See also concealment, cover, defilade, hull down, and turret down.) See FMs 7-7, 17-12, 17-15 and 23-1.

high-angle fire (JP 1-02, NATO) - Fire delivered at angles of elevation greater than the elevation that corresponds to the maximum range of the gun and ammunition concerned; fire, the range of which decreases as the angle of elevation is increased. (Army) - Fire delivered to clear an obstacle (such as a hill) that low-angle fire cannot, or fire delivered to attack targets on the reverse side of an obstacle (such as a hill) that cannot be attacked with low-angle or direct fire. See FMs 6-series and 7-90.

high-density airspace control zone (HIDACZ) (JP 1-02) - Airspace designated in an airspace control plan or airspace control order, in which there is a concentrated employment of numerous and varied weapons and airspace users. A high-density airspace control zone has defined dimensions, which usually coincide with geographical features or navigational aids. Access to a high-density airspace control zone is normally controlled by the maneuver commander. The maneuver commander can also direct a more restrictive weapons status within the high-density airspace control zone. (See also airspace coordination area (ACA) and restricted operating zone (ROZ).) See FMs 1-111 and 100-103.

high-payoff target (HPT) - A target that starts out as a high-value target but, because of its increased potential for providing decisive results, becomes a high-payoff target. (See also battlefield coordination element (BCE) and high-value target (HVT).) See FM 6-20 series.

high-value target (HVT) - A target whose loss to the enemy can be expected to contribute to substantial degradation of an important battlefield function. (See also battlefield coordination element (BCE) and high- payoff target (HPT).) See FM 6-20 series.

highway regulation - Planning, routing, scheduling, and deconflicting the use of main supply routes and other routes to provide order, prevent congestion, enforce priorities, and facilitate movement control. (See also main supply route (MSR) and alternate supply route (ASR).) See FMs 19-1 and 55-2.

HL - The symbol for a blister agent consisting of mustard-lewisite mixture. See FM 3-9.

HN - The symbol for nitrogen mustard, a blister agent. See FM 3-9.

hold (JP 1-02, NATO) - 1. A cargo stowage compartment aboard ship. 2. To maintain or retain possession of by force, as a position or an area. 3. In an attack, to exert sufficient pressure to prevent movement or redisposition of enemy forces. 4. As applied to air traffic, to keep an aircraft within a specified space or location which is identified by visual or other means in accordance with air traffic control instructions. (See also block, fix, and retain.) See FMs 7-7, 7-8, 7-10, 7-20, 7-30, 17-15, 17-95, 71-100, 71-123, 100-5, and 100-15.

hold fire (JP 1-02, NATO) - In air defense, an emergency order to stop firing. Missiles already in flight must be prevented from intercepting, if technically possible. See FM 44-100.

holding area (Army) - 1. A site located between assembly areas or forward arming and refueling points and battle positions (BPs) that may be occupied for short periods of time by attack helicopters while coordination is being made for movement into BPs. It should provide good cover and concealment and an area for the aircraft to hover or land. See FMs 1-111, 1-112, and 1-116. 2. Nearest covered and concealed position to the pickup zone or river crossing site where troops are held until time for them to move forward. See FMs 7-8, 7-10, 7-20, 7-30, 71-100-2, 71-100-3, and 90-13. 3. Waiting area that forces use during traffic interruptions or deployment from an aerial or seaport of embarkation. See FMs 19-1 and 55-2.

holding line (Army) - In retrograde river crossing operations, the outer limit of the area established between the enemy and the water obstacle to preclude direct and observed indirect fires into crossing areas. (See also bridgehead line.) See FMs 7-30, 71-100, 71-123, 90-13, and 100-15.

hospital (JP 1-02) - A medical treatment facility capable of providing inpatient care. It is appropriately staffed and equipped to provide diagnostic and therapeutic services, as well as the necessary supporting services required to perform its assigned mission and functions. A hospital may, in addition, discharge the functions of a clinic.

hostage (JP 1-02) - A person held as a pledge that certain terms or agreements will be kept. (The taking of hostages is forbidden under the Geneva Conventions, 1949.) See FM 100-20.

host country (JP 1-02) - A nation in which representatives or organizations of another state are present because of government invitation and/or international agreement. (See also civil military operations (CMO) and host nation). See FMs 100-5 and 100-20.

hostile (JP 1-02) - A contact positively identified as enemy. (Army) - An individual, a group of individuals, or a nation which is antagonistic or opposes policies and actions of the United States and its allies. The actions of a hostile can be political, diplomatic, or at any level of war. See FM 100-20.

hostile acts (JP 1-02) - Basic rules established by higher authority for defining and recognizing hostile acts by aircraft, submarines, surface units, and ground forces that will be promulgated by the commanders of unified or specified commands, and by other appropriate commanders when so authorized.

hostile casualty (JP 1-02) - A person who is the victim of a terrorist activity or who becomes a casualty "in action." "In action" characterizes the casualty as having been the direct result of hostile action, sustained in combat or relating thereto, or sustained going to or returning from a combat mission provided that the occurrence was directly related to hostile action. Included are persons killed or wounded mistakenly or accidentally by friendly fire directed at a hostile force or what is thought to be a hostile force. However, not to be considered as sustained in action and not to be interpreted as hostile casualties are injuries or death due to the elements, self-inflicted wounds, combat fatigue, and except in unusual cases, wounds or death inflicted by a friendly force while the individual is in an absent-without-leave, deserter, or dropped-from-rolls status or is voluntarily absent from a place of duty. (See also casualty and nonhostile casualty.)

hostile criteria - Description of conditions under which an aircraft or a vehicle may be identified as hostile for engagement purposes. (See also hostile acts and rules of engagement (ROE).)

hostile environment - See operational environment.

host nation - A nation which receives the forces and/or supplies of allied or coalition nations and/or NATO organizations to be located on, to operate in, or to transit through its territory. (See also civil military operations (CMO) and host country.) See FMs 100-5 and 100-20.

host nation support (JP 1-02) - Civil and/or military assistance rendered by a nation to foreign forces within its territory during peacetime, crises or emergencies, or war based on agreements mutually concluded between nations. (See also civil military operations (CMO).) See FMs 100-5, 100-10, and 100-20.

H-series agents - A series of persistent blister agents that include distilled mustard (HD), and the nitrogen mustards. See FM 3-9.

HT - The symbol for a mustard-T mixture, a blister agent. See FM 3-9.

hull down - The positioning of an armored vehicle so that the muzzle of the gun or launcher is the lowest part of the vehicle exposed to the front. Hull-down positions afford maximum protection for vehicles that are engaging targets with direct fire. (See also hide andturret down.) See FMs 7-7, 17-12, 17-15, and 23-1.

human intelligence (HUMINT) (JP 1-02, NATO) - A category of intelligence derived from information collected and provided by human sources. See FMs 34-2 and 34-3.

humanitarian assistance (HA) (JP 1-02) - Programs conducted to relieve or reduce the results of natural or man-made disasters or other endemic conditions such as human pain, disease, hunger, or privation that might present a serious threat to life or that can result in great damage to or loss of property. Humanitarian assistance provided by US forces is limited in scope and duration. The assistance provided is designed to supplement efforts of civilian authorities or agencies that may have primary responsibility for providing humanitarian assistance. See FMs 8-42 and 100-20.

humanitarian assistance coordination center (HACC) - Normally a subordinate element of the civil military operations center that deals directly with those agencies and organizations involved in humanitarian assistance efforts. In certain situations, particularly when participation for a specific operation by US armed forces is not extensive, a HACC can be formed as a separate, stand-alone organization. See FM 100-20.

humanitarian and civic assistance (HCA) (JP 1-02) - Assistance to the local populace provided by predominantly US forces in conjunction with military operations and exercises. This assistance is specifically authorized by Title 10, United States Code, section 401, and funded under separate authorities. Assistance provided under these provisions is limited to (1) medical, dental, and veterinary care provided in rural areas of a country; (2) construction of rudimentary surface transportation systems; (3) well drilling and construction of basic sanitation facilities; and (4) rudimentary construction and repair of public facilities. Assistance must fulfill unit training requirements that incidentally create humanitarian benefit to the local populace. (See also humanitarian assistance (HA).) See FMs 8-42 and 100-20.

hybrid collective protection - A combination of overpressure and ventilated face-piece systems. See FM 3-4.

hydrolysis - Interaction of a chemical agent with water to yield a less toxic product or products. See FM 3-9.

Updated 27 July 1997.

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