Compare the position of one node against another node in any other document,
returning a bitmask with the values from DocumentPosition.
Document order:
There is an ordering, document order, defined on all the nodes in the
document corresponding to the order in which the first character of the
XML representation of each node occurs in the XML representation of the
document after expansion of general entities. Thus, the document element
node will be the first node. Element nodes occur before their children.
Thus, document order orders element nodes in order of the occurrence of
their start-tag in the XML (after expansion of entities). The attribute
nodes of an element occur after the element and before its children. The
relative order of attribute nodes is implementation-dependent.
Compare the position of one node against another node in any other document, returning a bitmask with the values from DocumentPosition.
Document order:
Source: http://www.w3.org/TR/DOM-Level-3-Core/glossary.html#dt-document-order