Royalties and copyright fees: special income-tax spreading rules apply when literary or artistic work takes extended time to complete. Special rules govern the tax treatment of royalties or copyright fees for literary or artistic work where the author's work has taken more than twelve months to complete. Depending on whether the work took more than twelve but less than twenty-four months, or twenty-four months or more, the amount is spread over the year of receipt or receivability and the next one or two succeeding previous years. Where an allocation claim is made, tax is computed with adjustments reflecting the deferred inclusion.