nonmandatory

nonmandatory
    adj 1: not required by rule or law [syn: {nonmandatory},
           {nonobligatory}]
    

35 Moby Thesaurus words for "nonmandatory":
      arbitrary, autonomous, discretional, discretionary, elective, free,
      free will, gratuitous, independent, offered, optional, proffered,
      self-acting, self-active, self-determined, self-determining,
      spontaneous, unasked, unbesought, unbidden, uncalled-for,
      uncoerced, uncompelled, unforced, uninfluenced, uninvited,
      unpressured, unprompted, unrequested, unrequired, unsolicited,
      unsought, voluntary, volunteer, willful