The hierarchy of all Element Types available in the Data Source Model Type
associated with this template (see also "DSM Type Info" below).
On top of the tree are those element types, which are at the same time
-
Non-abstract (see below)
-
Never enclosed in other element types (as the types of possible children)
-
Never referenced from other element types (via the
IDREF
-values
of elements or attributes)
Those requirements mean that any root element of a Data Source Model
(which is the XML-like representation of a particular data source described by
the given DSM Type) most likely will have one of those types.