If a user doesn't have the Manage Promotions permission, the search function is disabled. (Otherwise, it would expose a vector for enumerating coupon codes to people who don't already have access to the list.) For this reason, it's possible to add ad-hoc codes to the field; If the codes are valid, the relations are saved.
However, in the case of someone with appropriate permissions, the ad-hoc “Add” functionality really shouldn’t show up. A code would appear in search or not be available at all.
If a user doesn't have the Manage Promotions permission, the search function is disabled. (Otherwise, it would expose a vector for enumerating coupon codes to people who don't already have access to the list.) For this reason, it's possible to add ad-hoc codes to the field; If the codes are valid, the relations are saved.
However, in the case of someone with appropriate permissions, the ad-hoc “Add” functionality really shouldn’t show up. A code would appear in search or not be available at all.