Section 28-501.3. Permit expiration

A permit issued pursuant to this article
  shall expire and be of no further force or effect where:
    1. In the case of a sign which is accessory to a principal use  within
  the  meaning of section 12-10 of the zoning resolution, there has been a
  discontinuance of the operation of the principal use to which such  sign
  is  accessory,  or  in  the  event  the  sign  is  no longer in the same
  ownership as such principal use or is no longer operated and  maintained
  substantially  for  the benefit or convenience of the owners, occupants,
  employees, customers or visitors of the principal use;
    2. In the case of any sign for which a permit has been issued pursuant
  to this article, whether or not accessory to a principal use within  the
  meaning  of  section  12-10  of  the zoning resolution, there has been a
  change in copy which the commissioner has determined renders  such  sign
  no  longer  in  compliance  with the zoning resolution. The commissioner
  shall  prescribe  by  rule  procedures  for  the  notification  to   the
  department  concerning changes in copy which have been made on signs for
  which permits have been issued under this article. Nothing herein  shall
  be  construed  as  limiting the ability of any person to apply for a new
  permit pursuant to this article.