STEP 1
Start at the order of review
§ 120.11 is mandatory. Identify general characteristics, pick a USML category, then match an enumerated paragraph before any catch-all.
STEP 2
Read the USML legend
Asterisks (SME) and the (MT) Missile Technology legend are in § 120.10. § 121.0 is the Part 121 local vocabulary (CCL, ECCN, EAR, DoD, and since 2026-10-13 ASE, Secured ASE, and Survivability-enhanced aircraft), not the MT legend. Headings are not controls. eCFR § 121.0 (FR 2026-17660): “ASE means Aircraft Survivability Equipment.” “Secured ASE means a system or equipment that meets all of the following conditions: (1) Is one of the following defense articles designed for the purpose of aircraft survivability: (i) Directed/directional infrared countermeasures (DIRCM) systems; or (ii) Infrared or ultraviolet missile warning systems necessary for the operation of DIRCM; (2) Is incorporated into an aircraft; and (3) Employs anti-tamper measures to deter, delay, and detect access to, or exploitation of, critical system components and software.” “Survivability-enhanced aircraft means a manned aircraft meeting all of the following criteria: (1) Prior to the modifications described in paragraph (2) of this definition, was an aircraft in production that: (i) Is not described on the USML; (ii) Is described only in ECCN 9A991.b; and (iii) Was issued either: (A) A type certificate by the U.S. Federal Aviation Administration as a transport airplane or small commuter airplane, or (B) An equivalent certification by the civil aviation authorities of one or more North Atlantic Treaty Organization member states or major non-NATO allies; (2) Has been modified to facilitate the incorporation of one or more items of secured ASE as defined in this section; (3) But for the modifications performed to incorporate secured ASE, would not be described in paragraph (a)(8) of USML Category VIII; and (4) Is not described in any USML paragraph other than paragraph (a)(8) of USML Category VIII.”
STEP 3
Open the matching category
Walk the enumerated paragraphs of § 121.1. Prefer an enumerated entry over a specially-designed catch-all when both could apply.
STEP 4
Apply specially designed
If a USML paragraph uses “specially designed,” that enumeration invokes § 120.41 — it is not the (a) test. Run (a)(1) (properties peculiarly responsible for the controlled performance) and (a)(2) (part/component/accessory/attachment/software for use in or with a defense article), then the (b) exclusions. A (b) exclusion does not auto-clear to the EAR or a 600-series ECCN; resume § 120.11. Unclear → CJ (§ 120.4). Document the (b) paragraph you rely on.
STEP 5
If it is not on the USML
After the USML is clear, § 120.11(d) and § 120.5 hand off to the other agency’s regime. For items that may be subject to the EAR, continue under Supplement No. 4 to Part 774 and Part 732. Do not treat § 120.58 as the classification step — it only defines “subject to the EAR.” A CJ (§ 120.4) is for genuine doubt, not for a paragraph you did not want to read.