Last year our group sent out a fax prior to our trip. I read this suggestion on another website. Sadly when we got there that request didn't even seem to exist...we had requested a specific building in the Cabana's at CSR. Upon arrival we were given a room in the Casitas. We asked if such builiding in Cabana was available. Oh sure!
Perhaps the fax wasn't received but it was the start to a very difficult check-in. We won't be staying at CSR again.