A Practice Note discussing ways to counsel clients on the creation of 4(c) and 4(d) documents submitted to the FTC and DOJ for their review during the Hart-Scott-Rodino (HSR) merger review process. This Practice Note explains the significance of 4(c) and 4(d) documents and provides strategies for searching for, selecting, and preparing 4(c) and 4(d) documents for filing with the HSR form. This Practice Note also discusses the potential liabilities for not filing all of these documents.