We just completed a stay at the Holiday Inn in Grapevine (DFW) Texas, a reservation I had made several months ago with the F&F rate.

As soon as I checked in I was asked for the F&F certificate - they didn't look at it, just took it an completed the process.

As a side note this was probably the one and only time I will check in as Platinum Elite (free status upgrade for a year) and if there was a benefit to having it, I couldn't tell you what it was. We had booked a king executive room, so maybe we had the best room possible as it was.