When setting up a Custom Field type Entry, there is the option to activate a Counter selector that allows to configure a Counter per Custom Field or a global Counter for all Entry Custom fields. A Counter is like a global variable that is incremented each time a number is allocated from it. It could for example be some kind of job number that is only allocated when some criteria is met. It's up to the User to allocate the number by pressing the little square button '+1' that is next to any Custom Field that has a Counter assigned to it.
Setting up a Counter
Create a new Entry Custom Field for example at Booking level. In the Counter selector, choose Configure. Now in the Counters table right-click and choose New. Give the Counter a name, for example "Edit Production #" and set what the Next Value should be. Press OK and once back in the Custom Field configuration window, select the Counter: Edit Production #. In this example we have also created a second Custom Field to have a Counter for Sound Production #. The idea is that all Edit Booking across all Projects that are for the Edit Department have their own numbering, and all Sound Bookings have their own.
Using the Counter
Continuing with the above example, once a Booking is created and the Booking Name Edit or Sound is populated, the User presses the +1 icon next to the Entry Custom Field so a new number is allocated from the Counter.