Exemption 4 is usually used by agencies to withhold trade secrets and confidential business information submitted to the government by private individuals and companies.
Under the exemption, an agency may withhold “trade secrets and commercial or financial information obtained from a person and privileged or confidential.”1 The exemption applies to two types of records. The first category of records that falls under Exemption 4 is trade secrets. The second category consists of information that is a) commercial or financial, and b) obtained from a person, and c) privileged or confidential.
This exemption is complicated and courts interpret differently by jurisdiction. As a result, what follows is a general explanation of the exemption.
1 5 U.S.C. § 552(b)(4).