The ranks of Cap­tain, Lieu­tenant and Sergeant are con­sid­ered posi­tions rather than assign­ments and per­sons meet­ing the require­ments of the qual­i­fi­ca­tions and appoint­ment pro­ce­dures stat­ed else­where in these Rules, Reg­u­la­tions and Pro­ce­dures can attain tenure in these posi­tions.  The Sher­iff, if appoint­ed to an unex­pired term from the ranks of tenured per­son­nel, reverts back to his tenured posi­tion and rank at the end of his term.