Check with your company Jumpseat Cordinator.
And there's, if you don't have an agreement with them.
Have your company J.S.C. try and get one.
I carry a list of who is allowed and who isn't,
our company actually prints us out one every year.
I've jumped with both these companies and they have been
very accomidating.
Rule number one.
1) Always have your ID and certificates ready.
2) Be courteous, it's a free ride.
3) Introduce yourself to the F.A. when able.
I through that in because recently I had a jumpseater
come into the cockpit unannouced and he didn't ask,
he told me he was riding up front with us. I still gave him
the ride but politely explained our procedures are the
same as his company and would appreciate the same
courtesy.