Below are the published ATSC standards for ATSC digital television service, issued by the Advanced Television Systems Committee. * A/49: Ghost Canceling Reference Signal for NTSC (for adjacent-channel interference or co-channel interference with analog NTSC stations nearby) * A/52B: audio data compression (Dolby AC-3 and E-AC-3) * A/53E: "ATSC Digital Television Standard" (the primary document governing the standard) * A/55: "Program Guide for Digital Television" (now deprecated in favor of A/65 PSIP) * A/56: "System Information for Digital Television" (now deprecated in favor of A/65 PSIP) * A/57A: "Content Identification and Labeling for ATSC Transport" (for assigning a unique digital number to each episode of each TV show, to assist DVRs) * A/63: "Standard for Coding 25/50 Hz Vid