Having access to the entire document will be needed when handling elements which refer to other elements. This is needed for e.g. <xref> or <link>, both of which reference other elements (by the 'id' attribute) for the label text. I suppose that in practice, the [Content] returned by parseXML always only contains one 'Elem' value -- the document element. However, I'm not totally sure about it, so let's just pass all the Content along.