17 CFR §230.166

1. (a)Communications. In a registered offering involving a business combination transaction, any communication made in connection with or relating to the transaction before the first public announcement of the offering will not constitute an offer to sell or a solicitation of an offer to buy the securities offered for purposes of section 5(c) of the Act (15 U.S.C. 77e(c)), so long as the participants take all reasonable steps within their control to prevent further distribution or publication of the communication until either the first public announcement is made or the registration statement related to the transaction is filed.
2. (b)Definitions. The terms business combination transaction, participant and public announcement have the same meaning as set forth in § 230.165(f).