This holds the hostname or IP address of the specific TACACS+ server this row's authorization statistics apply to, tracked separately from the address configured for that same physical server's authentication or accounting rows, since the MIB maintains each AAA phase's server list independently. An admin who wants command authorization to go to a different, more capable server than the one used for simple login authentication would set this address differently in the authorization table. For example, pointing authorization at a server with a richer command-set policy database while authentication continues to use a lighter-weight server.