Four Seasons may have parity across all retail booking channels, but it certainly also has lots of corporate and group rates. We can allow listing these rate codes so that those who don't know about them but are eligible to use them can do so.
For example, often if you are visiting a company as a customer, prospect, or potential employee, you are entitled to to use their corporate rate for that visit. The hotel can require you to prove that eligibility at check-in.