You now have the possibility to place bookings for invisible ticket categories via POS booking
How to set a price list to invisible?
- Go to manage offers > my offers and select the offer you want to edit
- In Step 3 "Tickets", you can find every ticket category for the offer
- deactivate the checkbox "Visible" for the ticket categories you chose to be invisible

How to place a POS booking for invisible price lists?
Booking an invisible ticket category via POS works exactly as a normal POS booking:
- bookings > new booking > choose your offer
You now can choose every ticket category for the offer, invisible ticket categories are labeled with the supplement "inactive"

After choosing an invisible ticket category, you can proceed with the booking as you are used to.