The United States has released detailed tariff classification codes covering steel and aluminum products subject to Section 232 national-security duties. Importers had previously relied on broader guidance; the publication of specific codes is expected to clarify compliance obligations as elevated levies remain in force. Separately, the U.S. Postal Service said that, starting 1 September, shippers of international commercial parcels must include a six-digit Harmonized System code on customs forms. Packages that lack the code risk being returned to sender, adding further pressure on exporters and e-commerce firms to tighten trade-compliance procedures.