So far, this book has focused on relatively straightforward mapping and simple transforms. As introduced in Chapter 1, Introducing the Concepts and Terminology, the tooling for transformation is built on industry standards around XML such as XSLT. We are not going to go in depth into these standards here, as to do the subject justice you would have to devote a whole book to it. There are plenty of texts on the subject, although we will show a bit more on the application of these standards within ICS as we go. Additionally, it is also worth noting that ICS will provide links to the relevant standards documentation within the mapping editor. The challenge this chapter is going to focus on is how we get additional information that you may need to complete a transformation, including activities such as variable use, lookups, and calling enrichment services.