NOx Reductions Under the Acid Rain Program - basically, you can set up an account with the EPA to monitor NOx allowances. Once you prove you're under the your allowance, you can report these numbers to the Chicago Climate Exchange for more carbon credits...I think. NOx allowances have less documentation than SO2 so the connection between establishing an allowance relationship is a grey area. Contact Steven John, the guy's information I sent you before, and he should be able to explain NOx cap and trade and setting up an account to trade NOx allowances to qualify for more carbon credits to sell.