15 C.F.R. § 2006.0
(c) The petitioner shall submit 20 copies of the petition in English, clearly typed, photocopied, or printed to: Chairman, Section 301 Committee, Office of the United States Trade Representative, 600 17th Street, NW., Washington, DC 20506.
To ensure proper docketing, petitions may be filed only during the following hours on days when the Federal Government is open for business: between 9 a.m. and 12 noon and 1 p.m. to 5 p.m.