In his prologue to the Opus Pacis, Oswald contrasts his work with the Valde Bonum, an earlier handbook compiled during the Great Schism. It had attempted to set forth universal spellings for the Bible, and stated that the corrector need not emend to conform to an exemplar from a given region based on its perceived superiority, but could rather take local regional practice as a standard. It acknowledged that centuries of use, and transmission from nation to nation, had an effect on various spellings. He incorporated many of these elements into his Opus Pacis, which was copied and put to practical use, and had spread from Germany as far north as Ireland. By the 1480s, it had become a standard, specifically for the Devotio Moderna and the Reformed Benedictines. Opus Pacis became a generic term for any work of its kind. The last surviving copy was written in 1514, indicating that manuscript correction remained an important subject sixty years into the printed era.