What is the difference between an assigned stateroom and a guarantee or GTY stateroom?
An assigned booking means that you have a stateroom assigned to you and you are given a specific stateroom number. You can check a deck plan to see where your room is located and change it, if availability allows, if you do not like the location. A guaranteed booking is one that guarantees that you will get at the very least that specific category, but if availability allows, you can be upgraded to a higher (never lower) category. The trade-off is you are not able to choose a specific stateroom. It should be noted that some cruise lines may not allow a guaranteed booking until their inventory in that category runs low, but that is not the case with most cruise lines. When you have an assigned booking, there is still a possibility that you will be upgraded, but not without your agreement.