Hotel Reservation System - Red Circle with Exclamation point - Waitlist?

I'm a little curious what the term "waitlist" means in the hotel reservation system. Originally I had blocked out a Thursday night through Sunday and later realizing that competing on Sunday and driving back on a Sunday would prove to be a little much. So this week I circled back to reserve Sunday night as well and there was a "red circle with an exclamation point" on that day with a term called "waitlist" associated with it. Does anyone know what this means? Do I have a room for this night? I would call the hotel but it says specifically not to do that and when I email typically there is no response to that email address.