All allowable nodes are defined in the glossary. Properties of Nodes, parid0220 and following is the proper place to cover node properties and should be the only place where such properties are treated. Definitions, properties, behavior should be explained once and only once, with later usages making reference to that single place in the standard where the one definitive statement can be found. Otherwise we risk creating ambiguity and having users chasing over the standard to find all the information on a particular concept.