(a) The presiding officer of a hearing may issue subpoenas for any
witness or exhibit that he determines may be material and relevant to the
issues of the hearing. So far as possible, each party to the hearing shall
provide the witnesses and exhibits that he intends to present at the
(b) If any party to the hearing is unable to provide his necessary
witnesses and exhibits, he shall advise the presiding officer far enough
in advance that the presiding officer can determine whether he should
issue subpoenas for the desired witnesses or exhibits.