Pendant (or pennant) numbers have been used by individual ships of the Royal Navy for purposes of identification for more than one hundred years. They were also used in all the navies of the British Empire so that ships could be easily transferred from one navy to another without changing her number. They offer the simplest and clearest way to identify a ship, but until now there has been little in the way of consistent and accurate information, and certainly no single location where you can look up or research complete pendant numbers.

This book is designed as an easy-to-use reference work and as such is, in the main, composed of alpha-numeric listings to enable the user to find and identify warships by reference to ship name and to identify specific pendant numbers assigned to that name; or by pendant number to identify specific vessels assigned that number at various times.