The reason someone purchases or uses a reference title is for the
information contained within.  A reference application should not have
any of the following:

26. Inaccurate reference data.  Imagine you're a student doing a
  homework assignment, using the CDTV title as a reference work. Your
  teacher gives you an ``F'' because your facts are wrong.

27. Missing information.  If a menu, icon or other reference indicates
  that information relating to the subject matter is available, the
  information should be accessible from that point.  In other words, if
  something is selectable, it must present the data associated with it.

28. An inability to accept keyboard input, print, or save to disk even
  though most people will not be able to take advantage of these features
  at the moment.