Identify the kind of source
The library labels statutory text, Treasury regulations, agency publications, form instructions, and administrative information separately. They have different roles and are not interchangeable. Cornell LII is an independent legal-information publisher. The official U.S. Code provides government statutory text; eCFR is a continuously updated, unofficial electronic edition.
Make the reasoning inspectable
Study notes use original summaries, simplified numerical examples and links to relevant authorities. The reference library is a research navigation layer, not a reproduction of the full Code or a live legal database. A link does not establish that every exception or current development is covered.
Date the model, test the mechanics
The first release includes 2025 and 2026 ordinary federal rate data, explicitly scoped calculator models, and boundary and numerical checks. Calculators show their assumptions with the result. This review does not substitute for independent professional verification of a real filing position.
Correct and improve
Use academic correspondence to report a broken link, a calculation issue, or a clearer source. Include the page URL and a nonconfidential example. Do not send taxpayer documents. Publication launch and review date: November 15, 2026.