Some definitions for those pesky mobile phone acronyms
The MSL is known as the Master Subsidy Lock code. It is the main code used to program your phone, and access and change the settings of your phone.
This is the subsidy lock that the providers put on the phone so you have to stay with them to use your phone (you can unlock this).
The NAM is the electronic memory in the cellular phone that stores the telephone number and an electronic serial number. Phones with dual- or multi-NAM features offer users the option of registering the phone with a local number in more than one market. (from mobiledia,com)
(Preferred Roaming List)
The PRL is a list of information that resides in the memory of a digital phone. It lists the frequency bands the phone can use in various parts of the country. (The smaller bands within Cellular or PCS.) (from phonescoop)
(Electronic Serial Number) The unique identification number embedded in a wireless phone by the manufacturer. Each time a call is placed, the ESN is automatically transmitted to the base station so the wireless carrier’s mobile switching office can check the call’s validity. The ESN cannot easily be altered in the field. The ESN differs from the mobile identification number, which is the wireless carrier’s identifier for a phone in the network. MINs and ESNs can be electronically checked to help prevent fraud. (from mobiledia.com)