I think the folks at Eisai pharmaceuticals may have wanted to try saying the name of their new drug out loud a few times before designing the marketing campaign. (Either that or they are marketing geniuses counting on the internet to spread it virally, and I am playing right into their hands.)
From the print story: "Says Department of Revenue spokesman Mark Couch: 'We don't allow 'FU' because some people could read that as street language for sex.' "