BG96: What is MBN files and when should I select/activate it?

My BG96 module shows a couple MBN files by AT+QMBNCFG=“LIST”.
However, the module works even all of the MBN files are not selected nor activated.

Is it ok to not select any MBN file?
When should I select and activate a MBN file?

MBN file is a package for dedicate operator ,like AT&T , verizon , and common etc,

Nomally , module will select the right MBN file automatically , if you can register network normally , you do not need to care about it .

To disable MBN file , you can use the below AT cmd