The Catalogue of Books Printed in the XVth Century Now in the British Museum (British Library), generally referred to as BMC, is a monument in the history of the book. BMC followed on from the rearrangement of the Museum’s incunabula begun by Robert Proctor on the basis of the comprehensive survey of printing types and presses of the fifteenth century that he had published in 1898 as an ‘Index’ of the incunabula in the Museum and the Bodleian Library. The Index represented a working-out of the system he had developed for the identification of printers of the incunabula period on the basis of typographical material. The volumes of BMC extend Proctor’s principles by providing full descriptions of the incunabula in the collections of the British Museum and making revisions where necessary. The first part appeared in 1908, prepared by A.W. Pollard after Proctor’s death in 1903. The most recent part was published in 1985.