Hide a Rate Code from the Reservation Discount Code Dropdown and Availability Screen (Desktop)
Hiding a Discount Code means that the hidden code will not show in the Discount Code dropdown in a reservation nor in the Availability screen. This will only hide it from the local side, it will not deactivate the discount code online.
Path: Management > Rates > Discounts > Setup (icon on the right side)
Find the rate code you want to hide from the dropdown and change the "Show Avail" column from Yes to No.