1. 
   VFR ON TOP
   Flight in which a cloud ceiling exists but modified VISUAL FLIGHT RULES are in effect if the aircraft travels above the cloud layer.
   Found op http://www.aerofiles.com/glossary.html
   
   
2. 
   VFR-on-Top
   In United States aviation VFR-on-top is defined as ATC authorization for an aircraft operating under Instrument Flight Rules (IFR) to do so in visual meteorological conditions (VMC) at any appropriate Visual Flight Rules (VFR) altitude. A pilot receiving this authorization must comply with the VFR ...
   Found op http://en.wikipedia.org/wiki/VFR-on-Top
   
   

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