The rotations and be loosely pronounced "apple" which makes it easy to remember the order they rotate in....from there, you just need to know where you start. I know it sounds dumb, but our server mentioned this once, and it has helped me to keep track ever since.
PAL isn't a rotation (unless things have changed in the last 4 months). If you started in Parrot, you would be PLA--Parrot, Lumiere's, Animator's.
Which rotation you are on is loosely based on the age of the youngest child in your group. There is one rotation of primarily toddlers, one of "middle kids, and one of mainly teens and adults. The computer draws the splits based on the ages of the children on any given cruise. Realize that this is only a rough estimate as people who purchase the REAS package can request a specific rotation--actually, anyone can request a rotation, but you may not get the request. We always request a specific server, and are happy with any rotation that he is on for that cruise.
As a general rule, late seating has fewer young ones than early.....school breaks have more school aged children, etc...