Glossary of Terms and Definitions

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ACTION PLAN: (See Incident Action Plan.)

AEC - Assistant Emergency Coordinator A position of leadership within the ARES organization reporting to the EC.

AFSK - Audio Frequency Shift Keying - A digital mode of radio communications where the RF carrier stays on the air throughout the transmission and a modulating audio tone is shifted in frequency.

AGENCY: An agency is a division of government with a specific function, or a non-governmental organization (e.g., private contractor, business, etc.) that offers a particular kind of assistance. In ICS, agencies are defined as jurisdictional (having statutory responsibility for incident mitigation) or assisting and/or cooperating (providing resources and/or assistance). (See Assisting Agency, Cooperating Agency, and Multi-agency.)

AGENCY EXECUTIVE OR ADMINISTRATOR: Chief executive officer (or designee) of the agency or jurisdiction that has responsibility for the incident.

AGENCY DISPATCH: The agency or jurisdictional facility from which resources are allocated to incidents.

AGENCY REPRESENTATIVE: An individual assigned to an incident from an assisting or cooperating agency who has been delegated authority to make decisions on matters affecting that agency's participation at the incident. Agency Representatives report to the Incident Liaison Officer.

AIR OPERATIONS BRANCH DIRECTOR: The person primarily responsible for preparing and implementing the air operations portion of the Incident Action Plan. Also responsible for providing logistical support to helicopters operating on the incident.

ALLOCATED RESOURCES: Resources dispatched to an incident.

AM - Amplitude Modulation A modulation system where the carrier is modulated producing equal sidebands of varying amplitude

AMTOR - Amateur Teleprinting Over Radio. Uses time diversity to minimize the effects of fading. Sent in either ARQ or FEC mode.

APRS - Automatic Position Reporting System A packet based communication system where information from a Global Positioning System (GPS) is fed to another computer for display. This uses the UI (Unconnected Information) frames within Packet.

AQS - Amateur Quiessence System. A form of digital signaling.

AREA COMMAND: An organization established to: 1) oversee the management of multiple incidents that are each being handled by an Incident Command System organization; or 2) to oversee the management of a very large incident that has multiple Incident Management Teams assigned to it. Area Command has the responsibility to set overall strategy and priorities, allocate critical resources based on priorities, ensure that incidents are properly managed, and ensure that objectives are met and strategies followed.

ARECC - Amateur Radio Emergency Communication Course - The ARRL Field Services educational program for amateur radio operators to provide consistent basic training in ARES.

ARES - Amateur Radio Emergency Service - The ARRL Field Services program for organizing amateur radio operators into a reserve of trained emergency communicators.

ARQ - Automatic Repeat Request - AMTOR communication mode where a repeat is sent only when requested by the receiving station.

ARRL - American Radio Relay League - The national organization of amateur radio operators headquartered in Newington, CT.

ASSIGNED RESOURCES: Resources checked in and assigned work tasks on an incident.

ASSIGNMENTS: Tasks given to resources to perform within a given operational period, based upon tactical objectives in the Incident Action Plan.

ASSISTANT: Title for subordinates of the Command Staff positions. The title indicates a level of technical capability, qualifications, and responsibility subordinate to the primary positions. Assistants may also be used to supervise unit activities at camps.

ASSISTING AGENCY: An agency directly contributing tactical or service resources to another agency.

ATV - Amateur Television

AVAILABLE RESOURCES: Incident-based resources which are ready for deployment.


BASE: The location at which primary logistics functions for an incident are coordinated and administered. There is only one Base per incident. (Incident name or other designator will be added to the term Base.) The Incident Command Post may be collocated with the Base.

BRANCH: The organizational level having functional or geographic responsibility for major parts of incident operations. The Branch level is organizationally between Section and Division/Group in the Operations Section, and between Section and Units in the Logistics Section. Branches are identified by the use of Roman Numerals or by functional name (e.g., medical, security, etc.).


CACHE: A pre-determined complement of tools, equipment, and/or supplies stored in a designated location, available for incident use.

CAMP: A geographical site, within the general incident area, separate from the Incident Base, equipped and staffed to provide sleeping, food, water, and sanitary services to incident personnel.

CB - Citizens Band - An unlicensed radio service for personal communications using low power 27 Megahertz transceivers.

CERT - Citizens Emergency Response Team A program enabling citizens to organize into neighborhood response teams.

CHECK-IN: The process whereby resources first report to an incident. Check-in locations include: Incident Command Post (Resources Unit), Incident Base, Camps, Staging Areas, Helibases, Helispots, and Division Supervisors (for direct line assignments).

CHAIN OF COMMAND: A series of management positions in order of authority.

CHIEF: The ICS title for individuals responsible for command of functional sections: Operations, Planning, Logistics, and Finance/Administration.

CLEAR TEXT: The use of plain English in radio communications transmissions. No Ten Codes or agency-specific codes are used when utilizing Clear Text.

COMMAND: The act of directing and/or controlling resources by virtue of explicit legal, agency, or delegated authority. May also refer to the Incident Commander.

COMMAND POST: (See Incident Command Post.)

COMMAND STAFF: The Command Staff consists of the Information Officer, Safety Officer, and Liaison Officer. They report directly to the Incident Commander. They may have an assistant or assistants, as needed.

COMMUNICATIONS UNIT: An organizational unit in the Logistics Section responsible for providing communication services at an incident. A Communications Unit may also be a facility (e.g., a trailer or mobile van) used to provide the major part of an Incident Communications Center.

COMPACTS: Formal working agreements among agencies to obtain mutual aid.

COMPENSATION UNIT/CLAIMS UNIT: Functional unit within the Finance/Administration Section responsible for financial concerns resulting from property damage, injuries, or fatalities at the incident.

COMPLEX: Two or more individual incidents located in the same general area which are assigned to a single Incident Commander or to Unified Command.

CONTROLLED NET A net, run by an NCS where all traffic is authorized by the NCS. Casual discussions are discouraged.

COOPERATING AGENCY: An agency supplying assistance other than direct tactical or support functions or resources to the incident control effort (e.g., Red Cross, telephone company, etc.).

COORDINATION: The process of systematically analyzing a situation, developing relevant information, and informing appropriate command authority of viable alternatives for selection of the most effective combination of available resources to meet specific objectives. The coordination process (which can be either intra- or inter-agency) does not involve dispatch actions. However, personnel responsible for coordination may perform command or dispatch functions within the limits established by specific agency delegations, procedures, legal authority, etc.

COORDINATION CENTER: Term used to describe any facility that is used for the coordination of agency or jurisdictional resources in support of one or more incidents.

COST SHARING AGREEMENTS: Agreements between agencies or jurisdictions to share designated costs related to incidents. Cost sharing agreements are normally written but may also be oral between authorized agency or jurisdictional representatives at the incident.

COST UNIT: Functional unit within the Finance/Administration Section responsible for tracking costs, analyzing cost data, making cost estimates, and recommending cost-saving measures.

CREW: (See Single Resource.)

CTCSS - Continuous Tone Coded Squelch System A form of sub-audible tone squelch that is used to minimize interference caused by intermodulation.

CW - Continuous Wave. A method of modulation where the carrier is turned on and off in a pattern that follows a known protocol. Usually the International Morse Code.


DCS - Digital Code Squelch - An advanced form of CTCSS. - A form of sub-audible tone squelch that is used to minimize interference caused by intermodulation.

DEC - District Emergency Coordinator. A position of leadership within the ARES organization reporting to the SEC.

DELEGATION OF AUTHORITY: A statement provided to the Incident Commander by the Agency Executive delegating authority and assigning responsibility. The Delegation of Authority can include objectives, priorities, expectations, constraints, and other considerations or guidelines as needed. Many agencies require written Delegation of Authority to be given to Incident Commanders prior to their assuming command on larger incidents.

DEPUTY: A fully qualified individual who, in the absence of a superior, could be delegated the authority to manage a functional operation or perform a specific task. In some cases, a Deputy could act as relief for a superior and therefore must be fully qualified in the position. Deputies can be assigned to the Incident Commander, General Staff, and Branch Directors.

DEMOBILIZATION UNIT: Functional unit within the Planning Section responsible for assuring orderly, safe, and efficient demobilization of incident resources.

DIRECTOR: The ICS title for individuals responsible for supervision of a Branch.

DISPATCH: The implementation of a command decision to move a resource or resources from one place to another.

DISPATCH CENTER: A facility from which resources are assigned to an incident.

DIVISION: Divisions are used to divide an incident into geographical areas of operation. A Division is located within the ICS organization between the Branch and the Task Force/Strike Team. (See Group.) Divisions are identified by alphabetic characters for horizontal applications and, often, by floor numbers when used in buildings.

DOCUMENTATION UNIT: Functional unit within the Planning Section responsible for collecting, recording, and safeguarding all documents relevant to the incident.

DSP - Digital Signal Processor - A high-speed numeric processor IC chip that filters audio signals to improve intelligibility of received information.

DTMF - Dual Tone Multi Frequency. A signaling and control method using two simultaneous tones. The same method as used in telephones.


EAS - Emergency Alert System. A system used by broadcasters to enable emergency management authorities to alert and inform the community via TV and radio.

EC - Emergency Coordinator. A position of leadership within the ARES organization reporting to the DEC.

ECom - Emergency Communication A set of instructional materials to provide consistent basic training in support of ARES. The source material was used for the ARRL's Continuing Education program in Emergency Communication (Amateur Radio Emergency Communication Course - ARECC).

EMERGENCY MANAGEMENT COORDINATOR/DIRECTOR: The individual within each political subdivision that has coordination responsibility for jurisdictional emergency management.

EMERGENCY MEDICAL TECHNICIAN (EMT): A health-care specialist with particular skills and knowledge in pre-hospital emergency medicine.

EMERGENCY OPERATIONS CENTER (EOC): A pre-designated facility established by an agency or jurisdiction to coordinate the overall agency or jurisdictional response and support to an emergency.

EMERGENCY OPERATIONS PLAN: The plan that each jurisdiction has and maintains for responding to appropriate hazards.

EOC - Emergency Operating Center - A facility designed to serve a focal point of operations during emergencies.

EVENT: A planned, non-emergency activity, usually in support of non profit organization, OR training. NOTE: Many training opportunities are given incident (ICS) names, yet are considered events, because they are planned.


FACILITIES UNIT: Functional unit within the Support Branch of the Logistics Section that provides fixed facilities for the incident. These facilities may include the Incident Base, feeding areas, sleeping areas, sanitary facilities, etc.

FCC - Federal Communications Commission - The federal agency with oversight of communications activities, including radio communications.

FEC - Forward Error Correction - One of the two modes of AMTOR communications. In this mode each character is sent twice.

FIELD OPERATIONS GUIDE: A pocket-size manual of instructions on the application of the Incident Command System.

FINANCE/ADMINISTRATION SECTION: The Section responsible for all incident costs and financial considerations. Includes the Time Unit, Procurement Unit, Compensation/Claims Unit, and Cost Unit.

FIPS - Federal Information Processing Standards codes. A system of five digit codes assigned by the federal government to designate each county in the country.

FM - Frequency Modulation - The frequency of the carrier is varied in accordance with the variations in modulating signal.

FOOD UNIT: Functional unit within the Service Branch of the Logistics Section responsible for providing meals for incident personnel.

FRS - Family Radio Service - an unlicensed radio service for personal communications using low powered (1/2 watt) UHF (460 MHz) transceivers.

FSK - Frequency Shift Keying - The transmitter shifts between two predetermined frequencies. The standard shift is now 170Hz.

FSTV - Fast Scan TV - An Amateur Radio image communication mode that closely resembles the picture quality available in commercial broadcast.

FUNCTION: In ICS, function refers to the five major activities in the ICS, i.e., Command, Operations, Planning, Logistics, and Finance/Administration. The term function is also used when describing the activity involved, e.g., the planning function.


GENERAL STAFF: The group of incident management personnel reporting to the Incident Commander. They may each have a deputy, as needed. The General Staff consists of:
Operations Section Chief
Planning Section Chief
Logistics Section Chief
Finance/Administration Section Chief

GENERIC ICS: Refers to the description of ICS that is generally applicable to any kind of incident or event.

GROUND SUPPORT UNIT: Functional unit within the Support Branch of the Logistics Section responsible for the fueling, maintaining, and repairing of vehicles, and the transportation of personnel and supplies.

GROUP: Groups are established to divide the incident into functional areas of operation. Groups are composed of resources assembled to perform a special function not necessarily within a single geographic division. (See Division.) Groups are located between Branches (when activated) and Resources in the Operations Section.


HELIBASE: The main location for parking, fueling, maintenance, and loading of helicopters operating in support of an incident. It is usually located at or near the incident base.

HELISPOT: Any designated location where a helicopter can safely take off and land. Some helispots may be used for loading of supplies, equipment, or personnel.

HF - High Frequency - the radio spectrum from 3 to 30 Megahertz.

HIERARCHY OF COMMAND: (See Chain of Command.)


ICS - Incident Command System - A management tool for command and control of emergency situations that is scalable to handle events of any size.

ICS NATIONAL TRAINING CURRICULUM: A series of 17 training modules consisting of instructor guides, visuals, tests, and student materials. The modules cover all aspects of ICS operations. The modules can be intermixed to meet specific training needs.

ID - Identification

IF - Intermediate Frequency - One of the frequencies used in a superhetrodyne receiver inbetween RF and audio.

INCIDENT: An occurrence either human caused or by natural phenomena, that requires action by emergency service personnel to prevent or minimize loss of life or damage to property and/or natural resources.

INCIDENT ACTION PLAN: Contains objectives reflecting the overall incident strategy and specific tactical actions and supporting information for the next operational period. The Plan may be oral or written. When written, the Plan may have a number of forms as attachments (e.g., traffic plan, safety plan, communications plan, map, etc.).

INCIDENT BASE: Location at the incident where the primary logistics functions are coordinated and administered. (Incident name or other designator will be added to the term Base.) The Incident Command Post may be collocated with the Base. There is only one Base per incident.

INCIDENT COMMANDER: The individual responsible for the management of all incident operations at the incident site.

INCIDENT COMMAND POST (ICP): The location at which the primary command functions are executed. The ICP may be collocated with the incident base or other incident facilities.

INCIDENT COMMAND SYSTEM (ICS): A standardized on-scene emergency management concept specifically designed to allow its user(s) to adopt an integrated organizational structure equal to the complexity and demands of single or multiple incidents, without being hindered by jurisdictional boundaries.

INCIDENT COMMUNICATIONS CENTER: The location of the Communications Unit and the Message Center.

INCIDENT MANAGEMENT TEAM: The Incident Commander and appropriate Command and General Staff personnel assigned to an incident.

INCIDENT OBJECTIVES: Statements of guidance and direction necessary for the selection of appropriate strategy(s), and the tactical direction of resources. Incident objectives are based on realistic expectations of what can be accomplished when all allocated resources have been effectively deployed. Incident objectives must be achievable and measurable, yet flexible enough to allow for strategic and tactical alternatives.

INFORMATION OFFICER: A member of the Command Staff responsible for interfacing with the public and media or with other agencies requiring information directly from the incident. There is only one Information Officer per incident. The Information Officer may have assistants.

INITIAL ACTION: The actions taken by resources which are the first to arrive at an incident.

INITIAL RESPONSE: Resources initially committed to an incident.

INCIDENT SUPPORT ORGANIZATION: Includes any off-incident support provided to an incident. Examples would be Agency Dispatch centers, Airports, Mobilization Centers, etc.

ITU - International Telecommunications Union


JNOS - A NOS (Network Operating System) that can be used as a platform for exchanging messages using a wide range of methods such as Internet, amateur radio, TCP/IP.

JURISDICTION: The range or sphere of authority. Public agencies have jurisdiction at an incident related to their legal responsibilities and authority for incident mitigation. Jurisdictional authority at an incident can be political/geographical (e.g., city, county, state, or federal boundary lines) or functional (e.g., police department, health department, etc.). (See Multijurisdiction.)

JURISDICTIONAL AGENCY: The agency having jurisdiction and responsibility for a specific geographical area, or a mandated function.


KIND: Refers to the nature of a resource i.e. Single, Strike Team, etc.


LANDING ZONE: (See Helispot.)

LEADER: The ICS title for an individual responsible for a Task Force, Strike Team, or functional unit.

LIAISON OFFICER: A member of the Command Staff responsible for coordinating with representatives from cooperating and assisting agencies.

LIFE-SAFETY: Refers to the joint consideration of both the life and physical well being of individuals.

LOGISTICS SECTION: The Section responsible for providing facilities, services, and materials for the incident.

LSB - Lower Sideband - The sideband below the base operating frequency.


MANAGERS: Individuals within ICS organizational units that are assigned specific managerial responsibilities, e.g., Staging Area Manager or Camp Manager.

MANAGEMENT BY OBJECTIVES: In ICS, this is a top-down management activity which involves a three-step process to achieve the incident goal. The steps are: establishing the incident objectives, selection of appropriate strategy(s) to achieve the objectives, and the tactical direction associated with the selected strategy. Tactical direction includes: selection of tactics, selection of resources, resource assignments, and performance monitoring.

MARS - Military Affiliate Radio Service

MEDICAL UNIT: Functional unit within the Service Branch of the Logistics Section responsible for the development of the Medical Emergency Plan, and for providing emergency medical treatment of incident personnel.

MESSAGE CENTER: The Message Center is part of the Incident Communications Center and is collocated or placed adjacent to it. It receives, records, and routes information about resources reporting to the incident, resource status, and administrative and tactical traffic.

MOBILIZATION: The process and procedures used by all organizations federal, state, and local for activating, assembling, and transporting all resources that have been requested to respond to or support an incident.

MOBILIZATION CENTER: An off-incident location at which emergency service personnel and equipment are temporarily located pending assignment, release, or reassignment.

MOU - Memorandum of Understanding: For our purposes, a written agreement between ARES/RACES groups and their Served Agency(ies). This agreement details what services will be provided by the ARES/RACES group and what commitment the Served Agency makes in return.

MRE - Meals Ready to Eat

MULTI-AGENCY INCIDENT: An incident where one or more agencies assist a jurisdictional agency or agencies. May be single or unified command.

MULTI-AGENCY COORDINATION (MAC): A generalized term which describes the functions and activities of representatives of involved agencies and/or jurisdictions who come together to make decisions regarding the prioritizing of incidents, and the sharing and use of critical resources. The MAC organization is not a part of the on-scene ICS and is not involved in developing incident strategy or tactics.

MULTI-AGENCY COORDINATION SYSTEM (MACS): The combination of personnel, facilities, equipment, procedures, and communications integrated into a common system. When activated, MACS has the responsibility for coordination of assisting agency resources and support in a multi-agency or multijurisdictional environment. A MAC Group functions within the MACS.

MULTIJURISDICTION INCIDENT: An incident requiring action from multiple agencies that have a statutory responsibility for incident mitigation. In ICS these incidents will be managed under Unified Command.

MUTUAL AID AGREEMENT: Written agreement between agencies and/or jurisdictions in which they agree to assist one another upon request, by furnishing personnel and equipment.


NATIONAL INTERAGENCY INCIDENT MANAGEMENT SYSTEM (NIIMS): An NWCG-developed program consisting of five major subsystems which collectively provide a total systems approach to all-risk incident management. The subsystems are: The Incident Command System, Training, Qualifications and Certification, Supporting Technologies, and Publications Management.

NATIONAL WILDFIRE COORDINATING GROUP (NWCG): A group formed under the direction of the Secretaries of the Interior and Agriculture to improve the coordination and effectiveness of wildland fire activities, and provide a forum to discuss, recommend appropriate action, or resolve issues and problems of substantive nature. The NWCG has been a primary supporter of ICS development and training.

NAWAS - National Warning System. The federal notification system used to inform and coordinate regional and national emergency management.

NET - Communications Network On the air meeting of Amateurs to handle messages and/or pass information relating to a scheduled or unscheduled event or incident. Small events may be conducted by an NCS. ALL incidents will start a net once there are more than two people working the incident.

NCS - Net Control Station The person charged with maintaining orderly flow of information during a net.

NIMS - National Incident Management System The National standard for Incident Management. This is ICS taken to a national level and is required training for any agency seeking Federal money.

NTS - National Traffic System - The ARRL organization of daily local, regional and national radio nets that passes messages nation-wide.

NOAA - National Oceanic and Atmospheric Administration. The administration under the federal Department of Commerce responsible for oceanic and atmospheric study.

NVIS - Near Vertical Incident Skywave. The mode of HF propagation that uses the ionosphere overhead as a reflector for a vertically radiated radio signal to provide omnidirectional signal pattern for HF coverage in a service radius of approximately 250 miles. Usually from a half-wave dipole mounted less than 1/8 wave length above ground (10 to 15 feet above ground functions very well).

NWR - National Weather Radio service. The 162 Mhz community radio service offered by the National Weather Service to provide timely weather information and alerts.

NWS - National Weather Service. The weather forecasting arm of the National Oceanic and Atmospheric Administration.


OFFICER: The ICS title for the personnel responsible for the Command Staff positions of Safety, Liaison, and Information.

OPEN NET A net that may be run by an NCS but only to designate who is to speak next. Casual conversation is accepted and traffic is handled on a first-come-first-served basis.

OPERATIONAL PERIOD: The period of time scheduled for execution of a given set of operation actions as specified in the Incident Action Plan. Operational Periods can be of various lengths, although usually not over 24 hours.

OPERATIONS SECTION: The Section responsible for all tactical operations at the incident. Includes Branches, Divisions and/or Groups, Task Forces, Strike Teams, Single Resources, and Staging Areas.

OSCAR - Orbiting Satellite Carrying Amateur Radio

OUT-OF-SERVICE RESOURCES: Resources assigned to an incident but unable to respond for mechanical, rest, or personnel reasons.

OVERHEAD PERSONNEL: Personnel who are assigned to supervisory positions which include Incident Commander, Command Staff, General Staff, Directors, Supervisors, and Unit Leaders.


Packet Radio - A digital mode of radio communications where the information is sent as a "packet" containing the call of the source and destination stations, error correction information and the data.

PACTOR - PACket Teleprinting Over Radio - A digital mode of radio communications usually found on frequencies between 1.8 Mhz. and 30 Mhz.

PBX - Private Branch Exchange

PLANNING MEETING: A meeting held as needed throughout the duration of an incident, to select specific strategies and tactics for incident control operations, and for service and support planning. On larger incidents, the planning meeting is a major element in the development of the Incident Action Plan.

PLANNING SECTION: Responsible for the collection, evaluation, and dissemination of tactical information related to the incident, and for the preparation and documentation of Incident Action Plans. The Section also maintains information on the current and forecasted situation, and on the status of resources assigned to the incident. Includes the Situation, Resource, Documentation, and Demobilization Units, as well as Technical Specialists.

PROCUREMENT UNIT: Functional unit within the Finance/Administration Section responsible for financial matters involving vendor contracts.

PSK - Phase Shift Keying - The phase angle of the transmitted signal is shifted in response to the modulating signal.

PSK31 - Phase Shift Keying 31 Baud - A point to point communication mode that works very well in low signal strength situations. World wide communication is possible with as little as one watt of output power.


RACES - Radio Amateur Civil Emergency Service - The FEMA program for organizing amateur radio operators registered with civil defense organizations into a reserve of emergency communicators.

RADIO CACHE: A supply of radios stored in a pre-determined location for assignment to incidents.

RECORDERS: Individuals within ICS organizational units who are responsible for recording information. Recorders may be found in Planning, Logistics, and Finance/Administration Units.

REINFORCED RESPONSE: Those resources requested in addition to the initial response.

REPORTING LOCATIONS: Location or facilities where incoming resources can check-in at the incident. (See Check-in.)

RESOURCES UNIT: Functional unit within the Planning Section responsible for recording the status of resources committed to the incident. The Unit also evaluates resources currently committed to the incident, the impact that additional responding resources will have on the incident, and anticipated resource needs.

RESOURCES: Personnel and equipment available, or potentially available, for assignment to incidents. Resources are described by kind and type, e.g., ground, water, air, etc., and may be used in tactical support or overhead capacities at an incident.

RF - Radio Frequency.

RIT - Receiver Incremental Tuning

RTTY - Radio teletype - A digital mode of radio communications.


SAFETY OFFICER: A member of the Command Staff responsible for monitoring and assessing safety hazards or unsafe situations, and for developing measures for ensuring personnel safety. The Safety Officer may have assistants.

SAME - Specific Area Message Encoding. A alert messaging scheme used by the National Weather Radio (NWR) service to alert specific counties of emergency conditions. SAME uses FIPS codes to address the counties.

SECTION: - ARES A Section within ARES is an administrative division of the ARRL Field Services organization. It will in many cases be a complete State (Colorado for example) or may be a portion of a State based on either population or land area (such as San Diego Section within California).

SECTION: - ICS That organization level with responsibility for a major functional area of the incident, e.g., Operations, Planning, Logistics, Finance/Administration. The Section is organizationally between Branch and Incident Commander.

SEC - Section Emergency Coordinator. A position of leadership within the ARES organization charged with leading a Section who reports to the Section Manager.

SECTOR: Term used in some applications to describe an organizational level similar to an ICS Division or Group. Sector is not a part of ICS terminology.

SEGMENT: A geographical area in which a task force/strike team leader or supervisor of a single resource is assigned authority and responsibility for the coordination of resources and implementation of planned tactics. A segment may be a portion of a division or an area inside or outside the perimeter of an incident. Segments are identified with Arabic numbers.

SERVICE BRANCH: A Branch within the Logistics Section responsible for service activities at the incident. Includes the Communications, Medical, and Food Units.

SINGLE RESOURCE: An individual, a piece of equipment and its personnel complement, or a crew or team of individuals with an identified work supervisor that can be used on an incident.

SITUATION UNIT: Functional unit within the Planning Section responsible for the collection, organization, and analysis of incident status information, and for analysis of the situation as it progresses. Reports to the Planning Section Chief.

SKYWARN - A network of community weather spotters serving the National Weather Service.

SM - Section Manager. A position of leadership within the ARRL Field Services organization just below national level.

SOP - Standard Operating Procedure

SPAN OF CONTROL: The supervisory ratio of from three-to-seven individuals, with five-to-one being established as optimum.

SSB - Single Side Band - A method of modulation where only one sideband is transmitted. The carrier and other sideband are suppressed.

STAGING AREA: Staging Areas are locations set up at an incident where resources can be placed while awaiting a tactical assignment. Staging Areas are managed by the Operations Section.

STRATEGY: The general plan or direction selected to accomplish incident objectives.

STRIKE TEAM: Specified combinations of the same kind and type of resources, with common communications and a leader.

SUPERVISOR: The ICS title for individuals responsible for command of a Division or Group.

SUPPLY UNIT: Functional unit within the Support Branch of the Logistics Section responsible for ordering equipment and supplies required for incident operations.

SUPPORT BRANCH: A Branch within the Logistics Section responsible for providing personnel, equipment, and supplies to support incident operations. Includes the Supply, Facilities, and Ground Support Units.

SUPPORTING MATERIALS: Refers to the several attachments that may be included with an Incident Action Plan, e.g., communications plan, map, safety plan, traffic plan, and medical plan.

SUPPORT RESOURCES: Non-tactical resources under the supervision of the Logistics, Planning, Finance/Administration Sections, or the Command Staff.


TACTICAL DIRECTION: Direction given by the Operations Section Chief which includes the tactics appropriate for the selected strategy, the selection and assignment of resources, tactics implementation, and performance monitoring for each operational period.

TASK FORCE: A combination of single resources assembled for a particular tactical need, with common communications and a leader.

TCXO - Temperature compensated crystal oscillator

TEAM: (See Single Resource.)

TECHNICAL SPECIALISTS: Personnel with special skills that can be used anywhere within the ICS organization.

TEMPORARY FLIGHT RESTRICTIONS (TFR): Temporary airspace restrictions for non-emergency aircraft in the incident area. TFRs are established by the FAA to ensure aircraft safety, and are normally limited to a five-nautical-mile radius and 2000 feet in altitude.

TIME UNIT: Functional unit within the Finance/Administration Section responsible for recording time for incident personnel and hired equipment.

TNC2 - Terminal Node Controller, Version 2 - A piece of equipment for packet radio communications.

Transceiver - A radio that combines a transmitter and receiver into one unit.

TYPE: Refers to resource capability. A Type 1 resource provides a greater overall capability due to power, size, capacity, etc., than would be found in a Type 2 resource. Resource typing provides managers with additional information in selecting the best resource for the task.


UHF - Ultra High Frequency - The radio spectrum from 300 to 3,000 Megahertz

UNIFIED AREA COMMAND: A Unified Area Command is established when incidents under an Area Command are multijurisdictional. (See Area Command and Unified Command.)

UNIFIED COMMAND: In ICS, Unified Command is a unified team effort which allows all agencies with responsibility for the incident, either geographical or functional, to manage an incident by establishing a common set of incident objectives and strategies. This is accomplished without losing or abdicating agency authority, responsibility, or accountability.

UNIT: The organizational element having functional responsibility for a specific incident planning, logistics, or finance/administration activity.

UNITY OF COMMAND: The concept by which each person within an organization reports to one and only one designated person.

USB - Upper Sideband - The sideband above the base operating frequency.


VHF - Very High Frequency - The radio spectrum from 30 to 300 Megahertz.

VOAD - Volunteer Organizations Active in Disasters

VOM - Volt-Ohm Meter

VOX - Voice Operated Transmit - a circuit that will cause a transmitter to automatically transmit when the microphone picks up voice or loud sounds.


XIT - Transmit Incremental Tuning