It was here that I read it: http://home.att.net/~jbaugher1/f4_9.html
Initially, the RF-4C carried no weapons, and the underfuselage Sparrow missile slots of the F-4C were omitted. However, in an emergency the RF-4C could carry a nuclear weapon on the centerline position, but this was rarely done in practice. Aircraft from the European-based 10th TRW were eventually fitted with AJB-7 low-altitude bombing system system equipment just in case the delivery of nuclear weapons ever became necessary. In later years, RF-4Cs were armed with AIM-9 Sidewinder missiles carried on the inner underwing pylon for self-defense. Provision was also made for carrying an electonic countermeasures pod on the inboard pylon underneath the starboard wing, the Westinghouse AN/ALQ-115(V)-15 or Raytheon AN/ALQ-184(V)1 being typical.