These suffixes denote what navigation and transponder equipment is avaliable for the aircraft, as filed in the flight plan by the pilot. Be alert as to the equipment avaliable on the aircraft and issue vectors accordingly.

• Some transponders are equipped with a MODE C automatic altitude reporting capability. This system converts aircraft altitude in 100 foot increments to coded digital information which is transmitted together with MODE C framing pulses to the interrogating radar facility. The manner in which transponder panels are designed differs, therefore, a pilot should be thoroughly familiar with the operation of the transponder so that ATC may realize its full capabilities.
• Pilots of aircraft with operating MODE C altitude reporting transponders should report exact altitude or flight level to the nearest hundred foot increment when establishing initial contact with an ATC facility. Exact altitude or flight level reports on initial contact provide ATC with information that is required prior to using MODE C altitude information for separation purposes. This will significantly reduce altitude verification requests.