- This booklet serves as an introduction to the series Illustrated Inventory of Medieval Manuscripts. It provides a census and checklist of all medieval manuscripts in Latin script which are known to exist (it should therefore proceed in shelf-mark order, collection by collection). The IIMM principles are: 1. IIMM must aim at completeness, that is exhaustive coverage; 2. of every manuscript there should be given, not only a description, but also a photograph; 3. if IIMM is to the be of any use in our lifetime, it must be executed with great speed, thus aiming for simplicity and low cost; 4. IIMM must be uniform.