Final answer:
Treasury Decisions are published first in the Internal Revenue Bulletin, which serves as the official instrument for announcing IRS rulings and procedures. They may subsequently be included in the Code of Federal Regulations, with initial proposals often appearing in the Federal Register.
Step-by-step explanation:
Treasury Decisions are published first in the Internal Revenue Bulletin (IRB), officially. The IRB serves as the authoritative instrument for announcing official rulings and procedures of the Internal Revenue Service and for publishing Treasury Decisions, Executive Orders, Tax Conventions, legislation, court decisions, and other items of general interest.
Treasury Decisions include a range of materials, such as temporary or final Treasury regulations and other official Treasury and IRS pronouncements. Following their publication in the IRB, these decisions may also be published in the Code of Federal Regulations (CFR), which is a codification of the general and permanent rules published in the Federal Register by the executive departments and agencies of the Federal Government.
The Federal Register, on the other hand, is the official journal of the federal government of the United States that contains government agency rules, proposed rules, and public notices. It is often the first place where newly proposed federal regulations are published.