Since its formation in 1664 the Royal Marines has been on of the armed forces’ most versatile units. This privately published Pocket Book’s format shows how often it would have been referred to: the practical curving of the corners of the pages allowed easy access to the book to and from pockets. Between the covers there is a range of information which would prove useful to a Royal Marine, including illustrations of army ranks, a diagram of the semaphore alphabet to aid ship to ship communication, and in-depth instructions on operating and maintaining a machine gun written by a machine gun officer.