 Hand cancellation is often used when sending unusually shaped mail or formal mail (e.g., wedding invitations) to avoid damage caused by machine cancellation.Postal meter stamps and similar modern printed to order stamps are not ordinarily cancelled by postal authorities because such stamps bear the date produced and can not readily be re-used.The United States Postal Service distinguishes between special cancellations which have a caption publicizing an event, and pictorial cancellations, which contain an image of some sort.