In issuing to the Police Force the new badge to be worn when the men are on Duty, the Superintendents will fully explain that the object in view is to prevent the constant complaints that would be made by the public on seeing those of the Police Force who are not on Duty walking or talking together, which they will not be able to do without that unpleasant consequence; the badge will be worn on the left arm, just above the cuff.
Source: Metropolitan Police. Instructions Orders &c. &c.1836. London: W. Clowes & Sons.