AIM - RAC 1.9. 5 - Phraseology

ATS personnel will use the following phraseology when referring to transponder
operation:

SQUAWK (code)     – Operate transponder on designated code in Mode A.

SQUAWK IDENT     – Engage the “IDENT” feature of the transponder.

NOTE: A pilot shall operate the identification

(“IDENT”) feature only when requested by an ATS unit.

SQUAWK ALTITUDE     – Activate Mode C with automatic altitude reporting.

STOP SQUAWK MODE     – Turn off automatic altitude reporting function.
CHARLIE

RECYCLE TRANSPONDER    – Reset your transponder, and transmit the SQUAWK
(code) currently assigned. This phraseology may be used if the target or identity tag data is not being
displayed as expected.

VERIFY YOUR ALTITUDE     – This phraseology may be used when it is necessary to validate altitude
readouts by comparing the readouts value with an altitude reported by the aircraft. An altitude readout is
considered valid if the readout value does not differ from the aircraft-reported
altitude by more than 200 ft, and invalid if the difference is 300 ft or more.

NOTE: Readout values are displayed in 100–ft
increments.