visual flight rules (VFR)

VFR traffic (visual flight rules)

visual flight rules

Rules of the Road (see: Navigation Rules)

instrument flight rules (IFR)

instrument flight rules operation

instrument rules flight

beyond visual range / beyond-visual-range (BVR)

visual flight

international rules in force

regulations, rules and policies

Rules of Engagement (ROE)

clearance rules

certification rules

aeronautical rules

air safety rules

design rules

flying safety rules

general operating rules

navigation rules

security rules

firing rules

udev rules are installed correctly

flight restriction zone / flight restricted zone (FRZ)

visual aids

visual communications

visual contact

visual identification

visual means

visual obscuration

visual tracking

within visual range (WVR)

antiaircraft artillery visual cueing system