The U.S. Supreme Court has added another type of document to its dustheap of once-respected resources for forming its opinions, along with law review articles and legislative reports.

The newly dissed artifact is called the Blue Book — not the Harvard Bluebook for citation styles, or the Kelley Blue Book that sets used-car prices. This Blue Book is published to explain new tax laws and is issued by the august Joint Committee on Taxation, an independent body composed of the top tax legislators in both houses of Congress.