In Reply to: Abbreviations posted by kevinrl on Monday, 4. June 2012 at 06:24 Bali Time:
Found this explanation on the net
Using only "W" as a reply is the same as rolling ones eyes or saying "your an idiot".
Or a shortened version of: "Your as stupid as George W Bush"
:)
Must admit i never did see these reply, the others are more familiar to me