When javac is invoked with -X, the help screen does not have the usage instruction two lines that are at the top of other help screens.
  "Usage: javac <options> <source files>
   where possible options include:"
It lists all the options in addition to the -X options,yet at the bottom it states, "These options are nonstandard and are subject to change without notice."
I think the javac -X help screen should have those same two usage lines at the top and the message at the bottom should be revised to say, "The -X options..."