What is the difference between Allstate's Fire and Casualty vs Property and Casualty?

Allstate Property and Casualty is a closed book of auto business that Allstate has had in the past. No new customers can be added to that book. If you are coming to Allstate for the first time in Florida you are placed into Allstate Fire and Casualty. So technically is just sub companies under Allstate. Auto companies accept new customers in a book until they reach a certain size and close it, then they open a new one for new customers. It is supposed to help maintain rate stability.