What qualifies as a so-called “4(c) document” under the premerger notification reporting requirements of the Hart-Scott-Rodino Act (HSR Act)?[1] It is a question that for close to a quarter-century has confounded parties submitting HSR filings. However, thanks to its recent and unprecedented enforcement action against Hearst Corporation, the government has made this antitrust puzzle a lot easier to figure out: just empty your files – or else.

4(c) Requirement