Luggage width advice

[ghostbiker]

a google might come up with the answer but i know there is a rule about there has to be a rear light within a set distance of the widest part of the bike, its a rule i became aware of when dabling in trike building years ago.
i doubt it would effect luggage as it was quite wide. there would be a law on if it was fully secured and not unsafe(unsecured/unsafe load)
but i would imagin it would have to be fairly extream to pull attention from the police.