Sorry, I don't know of any place on the web where this appears.

I would suggest you contact United Reservation, as they are the final authority on if and how many miles a fare will cost you. Not Mileage Plus. Any United Reservationist should be able to look up the rules and applicable fare codes.

It is also United Reservations that deducts or credits your account. Not Mileage Plus.

Sounds like you got a misinformed agent at Mileage Plus anyway.