Advanced Television Systems Committee(ATSC)
The Advanced Television Systems Committee (ATSC) (website)is a voluntary, member based organization that develops and publishes digital broadcasting standards. The ATSC is based in Washington, DC and it's standards have been adopted in large measure by the Federal Communications Commission.
In a hierarchial sense, ATSC, like it's peers at DVB, ARIB and SCTE, is an "MPEG User"
This web site contains information on Private table sections, descriptors, Programming Metadata Communications Protocol (PMCP)