Each document has a doctype attribute whose value is either NIL or a document type node. DOM level 1 provides an incomplete but useful interface to document types.
entities document-type
The entities attribute provides a named node map containing the entitiesdeclared in the DTD and doctype tag.
internal-subset document-type
The internal subset as a string.
name document-type
The name attribute provides the name of the DTD, i.e. the name immediately following the DOCTYPE keyword (which matches the root element).
notations document-type
The notations attribute provides a named node map containing the notations declared in the DTD and doctype tag.
public-id document-type
The public identifier of the external subset.
system-id document-type
The system identifier of the external subset.