It is possible to make a category visible to customers without allowing the products within it to be purchased. A message will be shown indicating that the category can only be ordered through the waiter.
Go to 'Categories' via the Manager and click on 'Edit' (go to detail page).
Disable the function 'Orderable via app' if you want to make the categorie visible but not orderable for the customer.
The message 'Order with waiter' is visible for the customer'.
