Better yet, get a CD-ROM tax library. There are several CD-ROM libraries available that include the I.R.C., regulations, court opinions, IRS pronouncements, and other information. They are word searchable and cheap. Look to commercial publications, treatises, and articles for help in understanding the concepts and finding cross-references. Finally, as in all legal research, make sure you check to see if the authority you wish to rely on is currently valid.
Tax laws change frequently.
Revenue Rulings and Revenue Procedures . If your factual situation is substantially the same as the one in the Revenue Ruling, you can be fairly confident in relying on the legal outcome stated in the Revenue Ruling. At the very least, reliance on the applicable Revenue Ruling will prevent penalties. Revenue Procedures provide guidance on IRS practice and procedural matters. Again, Revenue Rulings and Procedures do not undergo notice and comment and fall below final and temporary regulations in the pecking order.