Once again, I will tell my version of how the pork parting rule evolved. (Bunny, if you are reading this, please correct me if I am mistaken. I know you and Rich were around in 1993 when the pork rule was changed.)
Prior to 1993, the KCBS had little restrictions on what could be submitted as a pork entry. Country-style ribs from the loin were allowed to be submitted as a rib entry. They were also allowed as a pork entry as long as you had not submitted them as your rib entry. ANY cut of pork was allowed to be submitted as long as the cut was not spare or back ribs. This meant loin cuts, tenderloin, pork steak, economy style (shoulder cut) ribs, ham steaks, ham and any other pork cut could be submitted.
When the rule was changed to pork shoulder/Boston butt/picnic weighing at least five pounds, there were teams trying to circumvent this rule. Once the meat was inspected, some teams would cut the shoulder into smaller cuts such as economy style ribs or pork steaks. This brought about the clause about the parting rule that some people think makes no sense.