<prompt> Translate the following text to EnglishSheria za utaratibu wa Tume zinazosimamia mabadiliko yaliyopendekezwa katika ratiba ya uainishaji wa barua ziko katika sehemu ndogo ya C ya kichwa cha 39 cha Kanuni ya Kanuni za Shirikisho.  <response>: The Commissions procedural rules governing proposed changes in the mail classification schedule are contained in Subpart C of title 39 of the Code of Federal Regulations. 