In air traffic control, what does 'VR' signify?

The term 'VR' in air traffic control signifies "Visual Reference." This is important because it indicates a navigational aid or procedure that relies on visual landmarks or cues rather than solely on instruments or electronic guidance systems. Pilots often use visual references during flight to help with navigation and situational awareness, especially when flying in visual flight rules (VFR) conditions. Utilizing visual references is critical for ensuring aircraft maintain safe separation from terrain and other aircraft, particularly in areas where electronic navigation aids may not be present or reliable. While the other options pertain to various aspects of aviation and navigation, they do not reflect the standard meaning associated with 'VR' in air traffic control contexts.