Do you need a tracking code if bookings happen in a message?

A code is unnecessary while the booking is closed by message and written in the book. It is needed when the table is confirmed on a page of yours and you want to count that confirmation without asking on the floor. Say whether the booking ends in a message, a call or a page. A code is installed and the bookings are still a chat nobody cross-checks. The marked book, or the code only if the booking ends on the page.