Nuisance?

This very old inscription seen on the Welsh Bridge in Shrewsbury

"Commit no nuisance" Inscription on Welsh Bridge . It is the traditional euphemistic injunction against urination - although whether on the bridge or in the river is not clear. The words derive from C12th legal parlance, when such an act was a crime (it is a fineable offence today).

(In case you were wondering I was well behaved today)