Message Definitions (known as Messages in pre-4.5 versions), represent the foundation of your VMD file. Each message definition consists of three objects: Message Grammar, Identity and Transformation Script. This section explains how to create new custom message definitions to start building the basis of your VMD file. In addition, this chapter will also describe how to rename message definitions, how to use the message library and how to delete message definitions from your Workspace.

	Iguana Users Each Message Definition represents one HL7 message type inside your VMD file. A message definition is used by Iguana to identify incoming HL7 messages (in the case of parsing and transforming), or determine outgoing message types (in the case of generating). Note that you can have multiple messages set up in your VMD file.