<prompt> Translate the following text to EnglishTume pia ilibadilisha tarehe ya ufanisi wa mahitaji ya muhuri wa barua kutoka tarehe ya ufanisi wa ripoti na amri hadi Aprili 1, 1997, ili kuwapa waagizaji na wazalishaji wakati wa kufanya mabadiliko ya vifaa.  <response>: The Commission also changed the effective date of the letter stamping requirement from the effective date of the Report and Order to April 1, 1997, to give importers and manufacturers time to make equipment changes. 