Discrete code

{
  "id": "MLC-T-AVN-000331",
  "term": "Discrete code",
  "field": "Aviation and air traffic control",
  "definition": "As used in the Air Traffic Control Radar Beacon System (ATCRBS), any one of the 4096 selectable Mode 3/A aircraft transponder codes except those ending in zero zero; e.g., discrete codes: 0010, 1201, 2317, 7777; nondiscrete codes: 0100, 1200, 7700. Nondiscrete codes are normally reserved for radar facilities that are not equipped with discrete decoding capability and for other purposes such as emergencies (7700), VFR aircraft (1200), etc.",
  "synonyms": [
    "Discrete beacon code"
  ],
  "see_also": [
    "Radar"
  ],
  "references": [
    "AIM",
    "FAA Pilot/Controller Glossary"
  ],
  "url": "https://mlchart.com/terminology/aviation/discrete-code/"
}