The US Marine Corps has always had its own distinct language. The most apparent definition I found for this plate is "What Comes To Go In Order." In military jargon, that refers to the sequence of specific tasks or actions when assessing what resources can be mobilized to complete a mission. But there was also this, something I found initially during my search, interpreted as “What Can This GI Do,” but I couldn't find it a second time. All I can add is “Ooh-rah!”