Actually it is even a superset of XML, from the docs... SDL documents are made up of Tags. A Tag contains * a name (if not present, the name "content"

Actually it is even a superset of XML, from the docs... SDL documents are made up of Tags. A Tag contains * a name (if not present, the name "content" is used) * a namespace (optional) * 0 or more values (optional) * 0 or more attributes (optional) * 0 or more children (optional) So it's like an XML node, but the `0 or more values` means it has a list/array for a "body".