Section Notes, Chapter Notes, and Additional U.S. Notes: what each one does, with a worked example of each
Quick answer
Section Notes, Chapter Notes, and Additional U.S. Notes: what each one does, with a worked example of each
Section Notes govern a whole group of chapters, Chapter Notes govern one chapter, and Additional U.S. Notes are United States-specific definitions that route a classification within a heading, and all three are legally binding for classification the same as heading text itself. A vehicle gasket, a wall-hung bookshelf, and a footwear construction term each show a different note type overriding the intuitive, notes-blind answer.
GRI 1 says classification is determined by the terms of the headings and by any relative Section or Chapter Notes, which means the Notes are not background reading, they are part of the legal text that decides a classification exactly the way heading wording does. The HTSUS has three tiers of notes that operate at different levels, and candidates who only read heading text and skip the notes get real questions wrong. This guide separates the three tiers and works one example of each.
Section Notes: govern a whole group of chapters at once
The HTSUS groups its 99 chapters into 22 Sections, and a Section Note applies to every chapter inside that Section, not just one. Section XVII, for example, spans Chapters 86 through 89 (railway, vehicles, aircraft, and vessels), and Section XVII Note 2 excludes a specific list of items from the parts and accessories headings across the whole Section, even when an item is solely or principally designed for one of those vehicles.
Worked example. A parts distributor imports rubber gaskets designed specifically for automobile engines. Read only the heading text and 8708 (“parts and accessories of the motor vehicles of headings 8701 to 8705”) looks correct, since the gasket is solely used in a car. Section XVII Note 2 overrides that intuitive read: gaskets and similar joints are on the excluded list, so they are classified under their own dedicated heading (8484, gaskets and similar joints) instead of 8708, regardless of what vehicle they were designed for. See the transport equipment walkthrough for the full reasoning. A Section Note reaching across an entire Section to redirect a classification is what makes Section Notes the broadest-acting tier.
Chapter Notes: govern a single chapter
A Chapter Note applies only within its own chapter, and it typically defines what does or does not count as the subject matter of that chapter, or resolves boundary questions between that chapter and its neighbors.
Worked example. Chapter 94 covers furniture, and its own Chapter Note limits headings 9401 to 9403 to articles designed for placing on the floor or ground, with a named exception: shelved furniture such as cupboards and bookcases, and seats and beds, stay classified as furniture even when designed to be hung or fixed to a wall. Without reading that note, a wall-mounted bookshelf looks excluded from “furniture” on the ordinary meaning of the word. With the note, it is expressly included. See the miscellaneous manufactured articles walkthrough for the full scenario. A Chapter Note operating inside one chapter’s boundary, rather than across several chapters, is what distinguishes it from a Section Note.
Additional U.S. Notes: United States-specific, route within a heading
Section Notes and Chapter Notes are part of the internationally harmonized text used by every country on the World Customs Organization’s Harmonized System, which is why the first six digits of an HTSUS classification match the same product’s classification in most trading partner countries. Additional U.S. Notes are different: they are notes the United States adds on top of the harmonized text, and they typically define technical terms used to split a heading into its U.S.-specific eight- and ten-digit subheadings, rather than deciding the four-digit heading itself.
Worked example. Once a shoe is correctly placed in heading 6403 (footwear with a leather upper) using the material test in the footwear walkthrough, several of that heading’s U.S. subheadings turn on a defined construction term, “welt footwear,” rather than material alone. Chapter 64’s Additional U.S. Notes supply the technical definition of that construction, and the exam expects a candidate to look the term up rather than guess from the ordinary meaning of “welt.” Because Additional U.S. Notes are U.S.-specific, they never change which four-digit heading a good falls under; they only route the classification within a heading already settled by GRI 1 and the internationally harmonized Section and Chapter Notes.
Quick reference: the three note tiers
| Note type | Scope | Worked example |
|---|---|---|
| Section Note | An entire Section (multiple chapters) | Section XVII Note 2 pulls gaskets out of the vehicle-parts heading, 8708, across all of Chapters 86 to 89 |
| Chapter Note | One chapter only | Chapter 94’s floor-placement note keeps a wall-hung bookshelf classified as furniture |
| Additional U.S. Note | Within a heading, U.S.-specific subheadings only | Chapter 64’s definition of “welt footwear” routes a shoe already in heading 6403 to the correct subheading |
Why the exam tests this distinction
All three note types are legally binding on a classification the same way heading text is, but they act at different scopes, and knowing which tier a given note belongs to tells you how far its effect can reach. A Section Note can pull an item out of a heading that otherwise looks correct anywhere in that Section’s several chapters. A Chapter Note can only reach within its own chapter. An Additional U.S. Note cannot change the heading at all, only the subheading beneath it. A candidate who mixes these up might, for example, look for a footwear construction definition in a Section Note (footwear’s Section, Section XII, does not define “welt footwear,” Chapter 64’s Additional U.S. Notes do) and waste open-book time searching the wrong tier.
The practical open-book workflow: settle the heading first using GRI 1, the heading text, and any relevant Section or Chapter Notes; only after the heading is settled, check that chapter’s Additional U.S. Notes to route the subheading. Reversing that order, hunting for U.S. Note definitions before the heading is settled, wastes minutes the timed, tabbed exam does not give back. Practice the lookup itself with the Section and Chapter Notes trainer drill and the chapter locator.
Sources: the General Rules of Interpretation and the tiered structure of Section Notes, Chapter Notes, and Additional U.S. Notes as published in the Harmonized Tariff Schedule of the United States (hts.usitc.gov), reviewed 2026-07-29. Individual note texts referenced here (Section XVII Note 2, Chapter 94's floor-placement note, Chapter 64's footwear-construction Additional U.S. Notes) are described at a summary level; the notes are a public government work and this is a plain-English application, not a reproduction of the full legal text. Confirm current wording against the live HTSUS before relying on it.