JDK 8 includes 11 org.w3c.dom.** packages:
  org.w3c.dom
  org.w3c.dom.bootstrap
  org.w3c.dom.css
  org.w3c.dom.events
  org.w3c.dom.html
  org.w3c.dom.ls
  org.w3c.dom.ranges
  org.w3c.dom.stylesheets
  org.w3c.dom.traversal
  org.w3c.dom.views
  org.w3c.dom.xpath

Only five of them are endorsed in Java SE 8:
  org.w3c.dom
  org.w3c.dom.bootstrap
  org.w3c.dom.events
  org.w3c.dom.ls
  org.w3c.dom.views

This issue is to re-examine the supportedness of the six non-endorsed packages. After all, most of the non-endorsed packages are included in the Java Plug-in's "Common DOM API" [1] which is referenced from the Java Tutorial [2] and the JDK Deployment Guide [3] :
   org.w3c.dom.css
   org.w3c.dom.html
   org.w3c.dom.ranges
   org.w3c.dom.stylesheets
   org.w3c.dom.traversal

(org.w3c.dom.xpath is the sole non-endorsed package not included in the Common DOM API.)

[1] http://docs.oracle.com/javase/8/docs/jre/api/plugin/dom/
[2] http://docs.oracle.com/javase/8/docs/technotes/guides/jweb/decision_guide.html
[3] http://docs.oracle.com/javase/tutorial/deployment/applet/manipulatingDOMFromApplet.html

Until this issue is resolved, the java.xml module in JDK 9 will include all 11 packages but export only the five endorsed packages. The above docs should also be updated per the resolution of this bug.