[TOC]
This rule can be used to restrict transfers from/to only addresses inside a whitelist.
The default admin is the address put in argument(admin) inside the constructor. It is set in the constructor when the contract is deployed.
Here a schema of the Access Control.
It is possible to add the null address (0x0) to the whitelist. It is a requirement from the CMTAT to be able to mint tokens.
It is not a security problem because OpenZeppelin doesn't authorize the transfer of tokens to the zero address.
addAddress If the address already exists, the transaction is reverted to save gas. addAddresses If one of addresses already exist, there is no change for this address. The transaction remains valid (no revert).
removeAddress If the address does not exist in the whitelist, the transaction is reverted to save gas. removeAddresses If the address does not exist in the whitelist, there is no change for this address. The transaction remains valid (no revert).