Gadling picked this up via user Sel on Flickr, but no one on either of those sites has the foggiest idea what this sign means. I think our readers are smarter, however, so give it your best shot! (We're pretty sure it's not "no walking on hot coals," "it's forbidden to sleepwalk on a holey blanket" or "refrain from surfing shark-infested waters on perforated plywood," so you'll have to get more creative than that.)