One of my first jobs was in a tax office, I filed the new indexed tax laws and decisions into the volumes of tax law books that we had. They were printed in small type, both sides, on thin paper like they have in bibles.
Tax laws are ridiculous. If I did a tax return with an odd or questionable deduction, I would go through the tax books to find a tax case decision where the same circimstances were presented. Being the cases always had contradictions and opposing decisions, I would find one that had been decided in my clients favor and referenced it.

Forget trying to call the IRS for help. Most of those people don't know very much.