This attribute serves many purposes. The id value should be unique within an XML document. For each
element that has an id, it can be accessed later by an idref tag,
or be included any time by an include tag.
This attribute renames the current element to the tag name specified. Sometimes, for elements such
as varref only loads the object, but doesn't load the desired
set of adders and setters for the object. Rather, they rely on this attribute to be set in order
to load them.