Hungary’s Ministry of Environment and Water recently sold 800,000 certified emission-reduction credits. The credits had already been used in Hungary to offset emissions. The credits were evidently intended for in-country use by Japan. Under Japan’s program requiring the purchase of credits to offset emissions, the purchase of these credits was appropriate. But the credits, through continued trading, somehow found their way onto BlueNext, a Paris, France-based carbon credit exchange. European carbon exchanges do not allow used credits.