Add tag rule and a couple of comments.
Add tag rule and a couple of comments.

davidmoten/UMLGraph,davidmoten/UMLGraph,Edd123/UMLGraph,davidmoten/UMLGraph,Edd123/UMLGraph,dspinellis/UMLGraph,dspinellis/UMLGraph,Edd123/UMLGraph,dspinellis/UMLGraph