Unless I'm mistaken, the Hyatt Daily rate IS rack. If you're trying to use the points for an upgrade, the room type is pre-determined and is different for each hotel. For example, the time I tried to use it in Waikiki, I was told I had to book a minimum ocean view room at the daily rate.

There really is no rhyme or reason as to which rates would qualify - and I suspect discounted rates do not qualify. The only real way to find out it to call and ask for the property you're interested in.