operating system | Super Nintendo Entertainment System | Nintendo Entertainment System | Android (operating system) | Global Positioning System | Solar System | X Window System | Korean Broadcasting System | System of a Down | Domain Name System | Seoul Broadcasting System | North Carolina Community College System | transmitter | Mutual Broadcasting System | Bulletin board system | system | Turner Broadcasting System | Program and System Information Protocol | Geographic information system | Ubuntu (operating system) | Tokyo Broadcasting System | Federal Reserve System | Youth system | Embedded system | Automatic programming | solar system | Seigneurial system of New France | Interstate Highway System | Fedora (operating system) | Trans-Alaska Pipeline System |
Maritime identification digits are used by radio communication facilities to identify their home country or base area in Digital Selective Calling (DSC), Automatic Transmitter Identification System (ATIS), and Automatic Identification System (AIS) messages as part of their Maritime Mobile Service Identities.