Unfurl the pork if it’s boneless and cut along ... pork butt or just butt, and the lower portion, called the picnic shoulder, blade roast or picnic roast. They all can be labeled pork shoulder ...
The pork shoulder is large and typically separated into two cuts: the butt and the shoulder. These are also known as "blade roast" and "arm roast," respectively, or as "Boston butt" and "picnic ...
because preserved pork shoulders were shipped in the colonial era from Boston in barrels with the size designation “butt.” The lower part is (more obviously) labeled shoulder, shoulder roast ...