Using the MAKInterface and the propper software, a wide range of pagers from Motorola, Nec, Pantech, ... can be programmed.
What can be changed/customised, does depend on the pager model, you intend to programm and the available software.
Often the Motorola pagerscan handle up to 4 identification numbers. That means, you can recieve the messages from up to 4 pagers - your private one, the companys pager, etc.
Also the protokoll Pocsag/Flex, the baudrate, reception frequency, can be customised.