Does anyone know what Data Protection Opt Out regulations apply when customers phone their orders from printed mail order catalogue sources?

Must customers be given/reminded of their right to opt out at the call stage (i.e. exercise their right to not receive any further internal/external communications - mail, fax, email or phone from the supplier and not have their personal details passed onto any other third party source?) or is it sufficient to just carry this as a standard clause in the printed catalogue terms/conditions (i.e. write to us if this is something that you want us to do on your behalf)?

Anybody know?