28 If the imposition of control measures or steps
against a ship, pursuant to the provisions of SOLAS regulation XI-2/9, is considered necessary
these should be based, as far as possible, on a thorough assessment
of the prevailing security risks. Such assessments should be undertaken
on a non-discriminatory basis. When action is being considered on
the basis of information provided anonymously, or from non-official
sources, every effort should be made to confirm the authenticity of
the information.