Originally Posted by
mahasamatman
When they say stays using certs don't count, I think they mean free night certs, not upgrade certs. The only stay I ever had that didn't qualify was a free night redemption.
That's consistent with my understanding as well - only nights for which one uses free night certs may be considered non-qualifying.
In my experience, the stay will generally post as non-qualifying if one uses free night certs for all nights, but most of the time the IT system will ignore the free nights if you only use free night certs for part of your stay.