Air Force personnel are warned in a recent instruction not to track low observable (LO) or “sight sensitive” aircraft during test flights at Edwards Air Force Base.
“Low observable” is another term for stealth, and “sight sensitive” refers to objects that yield sensitive information simply by visual inspection.
“It is strictly forbidden to train tracking sensors (e.g. radar, infrared, electro-optical, personal cameras, sound recording devices, etc.) on any LO or sight-sensitive assets,” the Air Force instruction states.
“The single exception to this rule is to promote safety of flight.” Even then, “Recording of data will immediately terminate upon the termination of the flight safety incident.”
See “Security Procedures for Inadvertent Tracking and Sensor Acquisition of Low Observable and Sight Sensitive Programs,” Edwards Air Force Base Instruction 31-17, 14 November 2005 (thanks to RT).