Princess has been doing this for quite a while. Every so often someone will post this tip, which is good. Helps people get the cabin they want. I usually call my PVP and she takes care of it. Particularly useful for booking deluxe balconies. Deluxe balconies have a small couch, which can open up to a sofa bed serving three people. Princess policy of making large groups of cabins guarantee for various reasons is frustrating, but they aren't the only ones. NCL and Holland America have similar policies.