To libertarians wondering whether they can use bitcoins to avoid taxes, the IRS has a short, sweet answer for you: We're not sure.

Back in March, the Treasury Department issued a series of guidelines for bitcoin brokers. That guidance was more about registration requirements for brokers and money-laundering laws than it was about the tax implications of holding online currency.

But IRS spokesperson Anthony Burke told The Huffington Post that the agency hasn't yet clarified whether payments received in bitcoins should be considered barter, in-kind payments or payments in a foreign currency. Those aren't small distinctions, because each is treated differently under the tax code. There's also no sign of whether bitcoin donations to nonprofit organizations are deductible in U.S. dollars.