A tradition among enlisted Marines in which anyone senior in rank to a newly promoted Marine is allowed to punch the new rank insignia, thereby pinning them on. In the mid-to-late 20th Century, it became a custom for Recon Marines to have their jump wings literally pinned on their naked chests in violent and bloody rite of passage. The barbaric hazing was soon rooted out as a cultural anomaly and is hopefully a historic footnote. (synonym) Tacking On.