What transponder code indicates a hijacking or air piracy situation?

6-3-4. Special Emergency (Air Piracy)
a. A special emergency is a condition of air piracy, or other hostile act by a person(s) aboard an aircraft, which
threatens the safety of the aircraft or its passengers.
b. The pilot of an aircraft reporting a special emergency condition should:
1. If circumstances permit, apply distress or urgency radio-telephony procedures. Include the details of the
special emergency.
REFERENCE-
AIM, Para 6-3-1, Distress and Urgency Communications.
2. If circumstances do not permit the use of prescribed distress or urgency procedures, transmit:
(a) On the air/ground frequency in use at the time.
(b) As many as possible of the following elements spoken distinctly and in the following order:
(1) Name of the station addressed (time and circumstances permitting).
Distress and Urgency Procedures 6-3-7

AIM 2/20/25
(2) The identification of the aircraft and present position.
(3) The nature of the special emergency condition and pilot intentions (circumstances permitting).
(4) If unable to provide this information, use code words and/or transponder as follows:
Spoken Words
TRANSPONDER SEVEN FIVE ZERO ZERO
Meaning
I am being hijacked/forced to a new destination
Transponder Setting
Mode 3/A, Code 7500
NOTE-
Code 7500 will never be assigned by ATC without prior notification from the pilot that the aircraft is being subjected to
unlawful interference. The pilot should refuse the assignment of Code 7500 in any other situation and inform the controller
accordingly. Code 7500 will trigger the special emergency indicator in all radar ATC facilities.
c. Air traffic controllers will acknowledge and confirm receipt of transponder Code 7500 by asking the pilot
to verify it. If the aircraft is not being subjected to unlawful interference, the pilot should respond to the query
by broadcasting in the clear that the aircraft is not being subjected to unlawful interference. Upon receipt of this
information, the controller will request the pilot to verify the code selection depicted in the code selector windows
in the transponder control panel and change the code to the appropriate setting. If the pilot replies in the
affirmative or does not reply, the controller will not ask further questions but will flight follow, respond to pilot
requests and notify appropriate authorities.
d. If it is possible to do so without jeopardizing the safety of the flight, the pilot of a hijacked passenger aircraft,
after departing from the cleared routing over which the aircraft was operating, will attempt to do one or more
of the following things, insofar as circumstances may permit:
1. Maintain a true airspeed of no more than 400 knots, and preferably an altitude of between 10,000 and
25,000 feet.
2. Fly a course toward the destination which the hijacker has announced.
e. If these procedures result in either radio contact or air intercept, the pilot will attempt to comply with any
instructions received which may direct the aircraft to an appropriate landing field or alter the aircraft's flight path
off its current course, away from protected airspace.