<prompt> Translate the following text to EnglishKuhusu viwango, sheria ya 3622 b 6 inaweka kiwango cha maandalizi ya barua kwa ajili ya utoaji katika mfumo wa posta uliofanywa na mtoaji na athari yake juu ya kupunguza gharama kwa Huduma ya Posta kama sababu ya kuzingatia kuhusiana na mabadiliko yaliyopendekezwa.  <response>: Regarding rates, a 3622b6 establishes the degree of preparation of mail for delivery into the postal system performed by the mailer and its effect upon reducing costs to the Postal Service as a factor to be considered in connection with a proposed change. 