In Western Co. of North America v. United States, 323 F.3d 1024 (Fed.Cir. 2003), the Court recognized that the doctrine applies in circumstances in which the taxpayer's action involved a request for information. Western Co., 323 F.3d at 1035. The IRS mistakenly assessed the taxpayer a "failure-to-file" ("FTF") penalty. Id.; see also Western Co. of N. Am. v. United States, 52 Fed.Cl. 51, 54 (2002). The taxpayer, unaware of what had caused this penalty, repeatedly requested information about the basis for the penalty but did not file a formal claim for a refund. The IRS documented this request in writing. 323 F.3d at 1035. The Court held that the substantial variance doctrine did not bar the taxpayer's refund claim because, during the limitations period, Western had "repeatedly requested ... information that would have allowed filing of an informed claim," and thereby "put the IRS on notice of its challenges to the false assessment." Id. at 1034-35.