Originally Posted by
baseball
1. It's required by every 121 operator that I know of.
2. It's a professional courtesy to have it handy.
3. The CA is supposed to be mentoring his/her FO. Great opportunity for the CA to show some class and handle this introduction and interaction the right way.
The CA may only look at it for a second. But that checks the box. Security is still a big deal, so expect some Captains to ask a few questions about your airplane and/or operation/domicile.
I am over being lectured on this issue. It says specifically in our FOM that jumpseat riders flowing back to the cabin are not required to provide credentials to the PIC. You might review yours as well. And if you are the guy quizzing a commuter about his job/aircraft/whatever to "prove he is really a pilot" that is just plain wrong.