LogFAQs > #979619037

We know for sure that Edd/"Double D" is short for "Eddward" (it's been spoken aloud on rare occasions, like when Double D is trying to psyche himself up in Big Picture Show, and we've seen it written in at least the sticky note episode), but the other two aren't known. We do know all of their middle names, though, from the episode where Kevin found out about Eddy's and blackmailed him with it (Eddy's is "Skipper", Double D's is "Marion", and Ed's is "Horace").