TOPIC: adding ticket numbers

When we print actual tickets for an event and the tickets are numbered, we need to be able to track what ticket number was issued to each customer. We therefore need to have a field that we can input alphanumerical values into after the purchase and registration, but the field does not need to show up on the registration screen. so, it's only for reporting.

is this possible?

Yes, of course this is possible! Create a custom field and mark it as "hidden". Then assign the field to the event like you would any other field. The field will not show up on the frontend form... only in the backend when editing or creating records.