Although it is not a direct preventative or detective control, a banner can be used for these reasons:
Convey ownership.
Warn users of the acceptible use of the server.
Indicate that access or modifications to OpenBoot parameters is restricted to authorized personnel.
{0} ok setenv oem-banner banner-message {0} ok setenv oem-banner? true
The banner message can be up to 68 characters. All printable characters are accepted.