Finding rare books Records for much of the Rare Books Collection are in our Catalogue, but if you do not find the item you are looking for, please ask for help: the item may not yet be catalogued, or an alternative version may be available - for example in microform or online. In order to preserve the original, if the Library holds both an original and an alternative version, and your needs can be met by the alternative version, we will ask you to use this instead. The catalogue record for a rare book gives a call number with the prefix RB.