<prompt> Translate the following text to EnglishKwa upande mwingine, barua ya matangazo ni narrowly kufafanuliwa kama Kwanza-Class kusimama peke yake matangazo ya barua, yaani, Kwanza-Class Mail kutumika peke kwa ajili ya matangazo.  <response>: On the other hand, advertising mail is narrowly defined as First-Class stand-alone advertising mail, i.e., First-Class Mail used exclusively for advertising. 