22 CFR § 120.10 - Introduction to the U.S. Munitions List.
(a) The U.S. Munitions List. The articles, services, and related technical data designated as defense articles or defense services pursuant to sections 38 and 47(7) of the Arms Export Control Act appear in part 121 of this subchapter and constitute the U.S. Munitions List (USML). Changes in designations are published in the Federal Register. Paragraphs (b) through (d) of this section describe or explain the elements of a USML category.
(b) Composition of U.S. Munitions List categories. USML categories are organized by paragraphs and subparagraphs identified alphanumerically. They usually start by enumerating or otherwise describing end-items, followed by major systems and equipment; parts, components, accessories, and attachments; and technical data and defense services directly related to the defense articles of that USML category.
(c) Significant Military Equipment paragraphs in the USML. All items described within a USML paragraph or subordinate paragraph that is preceded by an asterisk (*) are designated Significant Military Equipment (SME). Note that technical data directly related to the manufacture or production of a defense article designated as SME is also designated as SME.
(d) Missile Technology Control Regime (MTCR) designation. Annotation with the parenthetical (MT) at the end of a USML entry indicates those defense articles that are on the MTCR Annex.