ACC                             Area Control Center

AFTN                           Aeronautical Fixed Telecommunication Network

AIDC                            Air Traffic Services Inter Facility Communication

AIRMET                     Information Concerning En-Route Affect the Safety of Aircraft Operations

AMHS                          ATS Message Handling System

AMSS                           Aeronautical Mobile Satellite Service 

ANC                             Air Navigation Commission

ARR                             Arrival

ATC                              Air Traffic Control

ATM                             Air Traffic Management

ATN                              Aeronautical Telecommunication Network

ATS                             Air Traffic Services                        

AU                                Access Unit 

CAA                             Civil Aviation Authority

CDN                             Co-Ordination

CHG                             Change

CIDIN                          Common ICAO Data Interchange Network

CLNS                           Connectionless Network Service

CNL                              Cancel

CNS                              Communication, Navigation and Surveillance

CNS/ATM                   Communications, Navigation, Surveillance/Air Traffic   Management

CONS                           Connection-Oriented Network Service

COTS                          Commercial off The Shelf – Software Products Developed for General Purpose Usage As Opposed To Bespoke Software

CPDLC                         Controller-Pilot Data Link Communication

CPL                              Current Flight Plan

DEP                              Depart or Departure

DEST                            Destination

DIR                               Directory Services

DLA                             Delay

DOC                             Document (ICAO)

EMERG                        Emergency

ETA                              Estimated Time of Arrival Or

FIC                               Flight Information Center

FP                                 Flight Plan

HF                                 High Frequency

ICAO                            International Civil Aviation Organization

ICS                               Internet Communications Services

IETF                             Internet Engineering Task Force

IMAP                            Internet Message Access Protocol

IP                                  Internet Protocol

ITU                               International Telecommunication Union

LLC                              Logic Link Control

MAC                             Medium Access Control

ME                                Message Store

METAR                        Aviation Routine Weather Report

MHS                             Message Handling System  

MMHS                          Military Message Handling System

MS                                Message Store

MTA                             Message Transfer Agent

OPMET                        Operational Meteorological  

OSI                               Open Systems Interconnect

OWA                            Outlook Web Access

POP3                            Post Office Protocol Version 3

RCAG                          Remote Communication Air-Ground

SARPS                         Standards And Recommended Practices-ICAO 

SEL                               Security

SMTP                            Simple Mail Transfer Protocol

SPECI                           Aviation Selected Special Weather Report

SSR                               Secondary Surveillance Radar

TAFOR                         Terminal Area Forecast

TCO                              Total Cost of Ownership

TCP                               Transmission Control Protocol

TWR                             Aerodrome Control Tower

UA                                User Agent

ULCS                           Upper Layer Communications Service

UTC                              Co-Ordination Universal Time

VHF                              Very High Frequency