O is an economy fare on CM. O is the Plat Elite BF Reward code.

But if you are viewing it on CO.com, CO.com only knows to look up its own codes, so it will display as BF on the website - but you really have O code of travel on CM. I am not sure if this is really a bug, since CO only translates its own codes.

Same has been true with other airlines as well on and how they show on CO.com. U on QF is reward Business, but it shows as coach - since U is coach on CO.