The authority behind Greco.

Greco grounds its research in official U.S. customs and trade sources.

Coverage reviewed August 19, 2026.

The U.S. tariff schedule

Navigate the full official HTSUS, including tariff provisions, section and chapter notes, footnotes, statistical detail, special programs, quotas, Chapter 99 measures, reference publications, and published duty rates.

  • Official Harmonized Tariff Schedule (HTSUS)
HTSUS provisions

Official CBP rulings

Compare product facts and issues against official New York and Headquarters rulings, or retrieve a known citation.

  • Official CBP CROSS Rulings
CBP NY and HQ rulings

Title 19 statutes and regulations

Read the official customs statute and regulations side by side, with each cited provision kept in context.

  • Official Title 19, Code of Federal Regulations
  • Official Title 19, United States Code
Title 19 passages

Export controls

Consult the official EAR and Commerce Control List for export-control questions. Classification and licensing remain professional decisions.

  • Official Export Administration Regulations and Commerce Control List
export-control references

OFAC sanctions lists

Review entries in the official OFAC SDN and Consolidated Non-SDN lists. Greco does not clear identities or make sanctions determinations.

  • Official OFAC Sanctions Lists
OFAC list collections

Current official guidance

Follow Federal Register notices, CBP messages, and signed presidential actions when a question turns on recent guidance.

  • Official Federal Register
  • Official CBP Cargo Systems Messaging Service
  • Official Presidential Actions
current source channels