The federal rules do not explicitly require privilege logs. However, the rules require a detailed description of any withheld documents, and most courts insist on or expect a log.
Some courts are more lenient. In Eli Lilly & Co. v. Valeant Pharmaceuticals International, Case No. 1:08-cv-1720-TWP-TAB, 2011 U.S. Dist. LEXIS 15246 (S.D. Ind. Feb. 15, 2011), defendant Valeant asked the district court to reverse a magistrate judge’s order allowing plaintiff Eli Lilly to withhold documents without logging them. The court agreed with the magistrate judge, noting “the tenuous connection between the requested documents and the core issues of the case.” Id. at *5. As the court explained it, “requiring Lilly to prepare a privilege log for documents that are marginally relevant to this garden-variety contract dispute would be unduly burdensome.” Id.
Only a handful of courts take such a forgiving view, but corporate litigants might consider seeking a similar ruling in the right circumstances.