A system of proof correction marks was developed by the early printers and gradually evolved over the succeeding centuries. In recent years this tradition has been challenged by a formal international standard (agreed by only fourteen countries—not including Ireland) that dispenses with the most widely understood traditional markings in favour of new inventions and replaces others with simplifications that obliterate their meaning.
We have available here a summary sheet illustrating the most commonly occurring proof correction marks of the kind traditionally used in the printing and publishing trades.