1. Blocking: This refers to the placement of the various actors and extras in a shot. When the assistant director tells you it's time to go over the blocking, it means that you have to go and be told where to stand and what to do during the shot. In short, it's what you actually do when the cameras roll.
2. Marks: These refer to the specific spot on which you are to stand during a scene. These are actual marks, usually made with tape or sandbags. If you don't stand at your mark, the camera won't focus properly. Extras are not usually given marks, but you need to know what the term means, (if someone tells you to "hit your mark," you need to go and stand on a piece of tape which should have been pointed out to you earlier).
3. Assistant Director: The assistant director, or A.D., is your boss. The A.D. is usually in charge of all the extras, and he or she is the person to whom you need to endear yourself. Assistant directors can help you in all sorts of ways, from not screaming at you and not firing you to getting you lines or letting you work for more money on a union voucher.
4. Taft-Hartleyed: To be "Tafted" or "Taft-Hartleyed" means to get into the extra union based on having worked on three union vouchers or by saying a line. The name comes from the Taft-Hartley labor law, the details of which we don't know and which don't concern you anyway. Just know that when people talk about Taft-Hartleying, they aren't uttering random syllables in an attempt to confuse you.
SoYouWanna know more? Check out our full-length article SYW be a movie extra?
