The Vatican Library's Vaticanus Latinus collection is one of its largest holdings. The majority of the codices between the shelf numbers 3000 and 9000 remain as yet to be cataloged according to modern standards. Professor Girard Etzkorn has cataloged over one hundred of these manuscripts selecting principally those pertaining to Franciscan authors and Franciscan history between the thirteenth and fifteenth centuries. He has successfully identified the authors of many treatises and sometimes entire works which were hitherto 'anonymous'. While the Iter Vaticanum Franciscanum focuses principally on manuscripts dealing with philosophy and theology, there are also codices which transmit texts on medieval astronomy, medicine, Canon Law, as well as numerous sermons, many of which have until now been unknown. The format of this catalog comprises three (sometimes four) categories: 1 the description, 2 a list of published editions, 3 annotations of historical, biographical or bibliographical importance noted in the codex and 4 a bibliography of 'post-medieval' books and articles about the codex and/or its contents.