May Contain Nuts

May Contain Nuts is the ubiquitous phrase found on all food packaging in Ankh-Morpork. It comes from the fact that Lord Vetinari takes proper food labeling very seriously, unfortunately he made the mistake of consulting the wizards advice on this with the question:

'Can you, taking into account multi-dimensional phase space, meta-statistical anomaly and the laws of probability, guarantee that anything with absolute certainty contains no nuts at all?'

When after several days of deep thought the wizards concluded that no it is not possible to be absolutely certain that something does not contain nuts, Lord Vetinari decided that labeling everything with May Contain Nuts would be more helpful then the label Probably Does Not Contain Nuts.

Annotation

The warning is also displayed at the top of most pages of this wiki, perhaps with more justification.
(The sitenotice has long since lost this warning, perhaps with less justification?)