Conrad Hilton, the founder of the Hilton chain, wrote a book called Be My Guest that can be found at some properties (I have seen it more than once).
It is telling that Hilton uses Be My Guest certificate to make it right for the guest when hotel has failed to provide expected level of service.
You can access Hilton HHonors here.
So, when you contact Hilton or Hilton HHonors and they refer your file to Guest Assistance, and when the hotel fails to reply to you or Hilton, you usually end up getting points or Be My Guest certificate with the brand printed on the front that failed.
The information on the certificate is very scant. It only tells that it is good for a standard room and that you need to hand in at the hotel.
You basically just need to make a reservation for the standard room that I have interpreted to be the room type that is available using points OR the room type if you have to you use Diamond override.
Just hand the certificate at the time of checking out and wait for the surprise!
You only should use one of these certs when the prices are expensive. I once used the cert for a villa at the Conrad Koh Samui (read more here) and at another time at the Hilton Palm Springs when the rates were through the roof due to an event.
When you check your account few days after your stay, you will probably find out that you got points for the full rate that got charged back to the offending property.
You may wonder how I ended up with one this time? My stay at the Rome Airport Hilton was less than stellar: rate was incorrect, room key didn’t work, internet was terrible, the priority check in desk was used to check in/out airline employees and could go on and on. Well. They now have $400 charge coming from Hilton Copenhagen airport!