On Wed, Mar 27, 2002 at 09:03:39PM +1100, matthew green wrote:
  |    For backwards compatibility purposes, if the now obsolete
  |    variable is defined (even empty), it takes precedence over
  |    the new form, and you will be warned. If you want to stop the
  |    warnings, update your rc.conf(5) settings!
  | 
  | thanks for the backwards compat.  please try to keep it for a while
  | as warnings are often missed.  particularly on machines with no
  | console connected :-)

fwiw, the warnings are also logged to user.notice by logger(1).