Sec.  1.225   Participation by non-parties; consideration of communications.

   (a) Any person who wishes to appear and give evidence on any matter and who
   so advises the Secretary, will be notified by the Secretary if that matter
   is designated for hearing. In the case of requests bearing more than one
   signature, notice of hearing will be given to the person first signing
   unless the request indicates that such notice should be sent to someone
   other than such person.

   (b) No person shall be precluded from giving any relevant, material, and
   competent testimony at a hearing because he lacks a sufficient interest to
   justify his intervention as a party in the matter.

   (c) When a hearing is held, no communication will be considered in
   determining the merits of any matter unless it has been received into
   evidence. The admissibility of any communication shall be governed by the
   applicable rules of evidence, and no communication shall be admissible on
   the basis of a stipulation unless Commission counsel as well as counsel for
   all of the parties shall join in such stipulation.