Annotations are only available in models targeted with XSD.
You define annotations when you want to add information about an XML model. There are three kinds of annotations:
Annotation - provides extra information on XML models or schemas. You can define multiple annotations at this level, and each can contain multiple documentation and/or application information tags.
Documentation – is contained within an annotation and contains an URI reference or any well-formed XML content that gives extra information about XML objects or documents
Application Information - is contained within an annotation and contains an URI reference or any well-formed XML content that is used by applications for processing instructions
Generated schema of a global annotation:
This global annotation is composed of a documentation, with a well-formed XML content (extract of a DTD file), and an application information.