S5:E4;2 MGS

In this episode's cold open Dwight tells Michael to mark the baby (a watermelon) with a mark only he would recognize and no baby snatcher could ever replicate. Later, when Dwight takes Jan's stroller outside to test its durability (11:33), we can see a mark written in black felt pen, with the letters "MGS" (Michael Gary Scott's initials) inside an ellipse on the watermelon.