The PM Line of Hoggs is simply another line... kinda like the Graziani and the NERD lines of pastels.

There were only a few people that collected Hoggies and brought them into the country... separate lines were created by the captive specimens. Bob Sears was one such collector. That's why you see the "Sears" Line of Hoggs. These are usually considered PURE hoggs because they come from a line that was directly collected from the island.

I can't remember what PM stands for off-hand, but it was another collector's line.