Publications Memos Go Back HSR Report Form Change to NAICS Codes 05.09.01 This memorandum deals with an interim rule effective July 1, 2001 that implements changes to certain reporting requirements on the Premerger Notification and Report Form under the Hart-Scott-Rodino Act. Related Insights 05.23.25 | Publications Supreme Court: Settles Circuit Split on Pleading Standards for Prohibited-Transaction Claims 05.20.25 | Publications New Guidance From the SEC’s Division of Trading and Markets Signals a Welcome Shift on the SEC’s Approach to Crypto Asset Activities and Distributed Ledger Technology 05.15.25 | Publications Simpson Thacher Sustainability and ESG: Regulatory Update – May 2025 Related Services Related Practice Areas Litigation Antitrust and Trade Regulation Complex Commercial Litigation