In this article, we present a model for transformation of resources in information supply. These transformations allow us to reason more flexibly about information supply, and cular its heterogeneous nature. They allow us to change the form (e.g. report, abstract, summary) and format (e.g. PDF, DOC, HTML) of data resources found on the Web. In a retrieval context these transformations may be used to ensure that data resources are presented to the user in a form and format that is apt at that time.