Originally Posted by TommyC80

You cannot use the club level certificate on point or free-night award stays. Also, The club level certificate is only valid against the best-available-rate for the hotel, in a room category that has both a club level and non-club level version. You can't use the cert with AAA rates, corporate rates, or with any hotel package that may be on offer.

For example, if there is a regular garden view room available for sale. But there are no garden view rooms on the club level, you cannot use the upgrade certificate.