The Radio Technical Commission for Maritime Services (RTCM) is a non-profit international standards organization. Although started in 1947 as a U.S. government advisory committee, RTCM is now an independent organization supported by its member organizations from all over the world.
RTCM Special Committees are formed to provide in-depth areas of concern to the RTCM membership, these special committees normally produce documents in the form of standards.
Current special committees are
Special Committee (SC) 101 on Digital Selective Calling (DSC)
Joint Special Committee (SC) 101/110 on GPS Equipped Hand Held VHF Radios
Special Committee (SC) 134 on Integrity for High-Accuracy GNSS Applications
Special Committee (SC) 135 on Radio Layers for Real-Time DGNSS Applications
Special Committee (SC) 136 on Beacon Type Approvals
Special Committee (SC) 137 on Electromagnetic Compatibility Requirements for LED Devices and other Unintentional Emitters Located Near Shipboard Antennas
Special Committee (SC) 138 on Ranging Mode (R-Mode) Application for VHF Data Exchange System (VDES)