(a) Messenger and/or learner certificates may be issued for a period
of not longer than one year.
(b) Each special apprentice certificate shall specify the conditions
and limitations under which it is granted, including the periods of time
during which subminimum wage rates may be paid pursuant to a registered
apprenticeship program.
(c) No certificate may be issued retroactively.
(d) The Administrator may amend the provisions of a certificate when
necessary to correct omissions or defects in the original certificate or
reflect changes in this part.