I have spoken to local hotels about discounted rates for our guests on our wedding night, and the one I would like to book a block with has a policy that we have to use at lease 70% of them - so if we booked a block of 10 and only 6 people booked with them, we'd have to pay for the one room that wasn't booked. I want to get a better idea of who will want to book a hotel room for the night, so I've put it as an option on my website when people RSVP. Are there any rules of etiquette about that? I worded it "Yes, I will need to book a hotel room" or "No, I will not need to book a hotel room" and explained that I'd like them to indicate that on the "guest information" page so that we can get an idea of how many rooms to block off. I don't want our guests to think that we're offering to pay for the rooms for them but I don't think I've implied that anywhere. What do you think? Is this ok to do?