To be exact I would like to know if entity and notation nodes can appear in a tree under the root element node? Does it make sense for E and N to have methods like next sibling if they really only live inside rhe named node construct?I m just wondering if it's wrong to have the Node super type being the ancestor of E n N. My foo mist be poor as I could not find any practical commentary or example to say otherwise. I can only assume the hierarchy was a compromise that's wrong. I realise there are other concepts in Node that shouldn't be there like the children stuff which doesn't make sense for text, comments and cdata.