Italian to English Tech/Engineering Mechanics / Mech Engineering

This is a term used in a technical manual.

Basically it says that you have to press this "pulsante di prenotazione start" button and the prenotazione start light turns on but the filing process will only begin after the other containers being filled are finished.

Reserve start button?
Delay start button?
Preparation to start button?

I suppose this button is sort of like when you go to the market and have to take a number so you know when it's your turn to be served.

Any ideas on the proper term for this type of button?