Originally Posted by FlyPurdue

Okay, rule of thumb - If they look you up in CASS, you are 'jumpseating' no matter if you are in the flight deck, a spare flight attendant seat, or in a comfy first class seat. If you are on the plane, without having been looked up in CASS, you are a non-rev. No matter if it is ZED, ID90,75 or 50, or a company vacation pass.

Remember:
CASS = Jumpseat = ask the captain for a ride.
No Cass = Non Rev = don't ask the captain for a ride.

Cheers!