If that's the case (and I'm not saying that it isn't - I just don't know) this causes me to harken back to the point about "explicitness" (actually, lack of same) in the T's and C's.

Here's T & C #4 as it appears on the certificate in question:

"4. Weekend nights are designated as Friday, Saturday and/or Sunday nights only. In some properties in the Middle East, weekend nights are designated as Thursday, Friday and Saturday Nights."

If a (domestic, non-resort) property does include Thursday within it's designation of weekend days perhaps something along the order of the italicized statements should be added to #4:

"4 Weekend nights are (with exceptions at various properties are designated as Friday, Saturday and/or Sunday nights only. However, certain properties occasionally designate Thursday as a weekend night valid under the Terms and Conditions of this offer. In some countries in the Middle East, weekend nights are designated as Thursday, Friday and Saturday nights.

I would also suggest that the first two statements appearing under the existing bold-faced heading "To take advantage of the offer" be highligted in some way -

* "Rooms must be confirmed in advance by calling your Elite Reservations Line."

* "Please advise agent that you will be using the Marriott Rewards Elite Exclusive Offer for the second night as the method of payment."