This is some information of Bluetooth Low Energy about the White List. I hope this information help you to understand the White List.
The device to connect is saved on the white list located in the LL block of the controller. This enumerates the remote devices that are allowed to communicate with the local device. Since device filtering occurs in the LL it can have a significant impact on power consumption by filtering (or ignoring) advertising packets, scan requests or connection requests from being sent to the higher layers for handling.
The Withe List can restrict which device are allowed to connect to other device. If is not, is not going to connect.
Once the address was saved, the connection with that device is going to be an auto connection establishment procedure.This means that the Controller autonomously establishes a connection with the device address that matches the address stored in the While List.
Figure 1. White List Procedure
For more details download the Specification of the Ble