Originally Posted by Slamdunkpro
That's the issue with IMPS numbers - IMPS only designates primal cuts. A "collar" seems to a sub cut of an IMPS 406 butt.
No and Yes. all sub primal cuts are recognized in these numbers and its not recognized. Just like the rules say butt, shoulder, and picnic. Not sub primal called pork steak, country style ribs, cushion meat, etc.
Here is the way a butt is described to be cut and still allowed to be called a butt. Any other way its not a butt:
The shoulder is separated from the side by a straight cut that is approximately perpendicular to the length of the side. The cut shall be made posterior to (so as not to expose) the elbow, but not more than 1.0 inch (2.5 cm) from the tip of the elbow. The outer tip of the subscapularis muscle shall not extend past the dorsal edge of the base of the medial ridge of the blade bone. The foot shall be excluded at or slightly above the upper knee joint by a straight cut approximately perpendicular to the shank bones. The jowl shall be excluded by a straight cut approximately parallel with the loin side which is anterior to, but not more than 1.0 inch (2.5 cm) from the innermost curvature of the ear dip. The neck bones, ribs, breast bones, associated cartilage and breast flap (through the major crease) shall also be excluded. The fat and skin shall be beveled to meet the lean on the dorsal edge. The exterior fat thickness at the dorsal skin edge, measured at the center of the cut, shall not exceed that indicated in the schedule shown.