In Coeur Alaska, Inc. v. Southeast Alaska Conservation Council (2009) 557 U.S. 261, one of the things the Supreme Court itself relied upon to discern the "agency interpretation and agency application of the regulations" (Coeur Alaska, supra, at p. 283) was a memorandum written by one agency official to another. In doing so, the court explained that "the Memorandum, though not subject to sufficiently formal procedures to merit Chevron U.S.A. Inc. v. National Resources Defense Council, Inc. (1984) 467 U.S. 837, deference, is entitled to a measure of deference because it interprets the agencies' own regulatory scheme." (Id. at pp. 283-284.)