"The Vaughn v. Rosen decision marked the beginning of a tool (and in some Circuits, a requirement) that is widely referred to as the 'Vaughn Index'--i.e., a list containing the information claimed as exempt and the corresponding exemption under which it is claimed. In Vaughn v. Rosen (D.C.Cir. 1973) 157 U.S. App.D.C. 340 484 F.2d 820, the plaintiff must argue that the agency from which information is sought has improperly withheld requested documents, even though only the agency knows their actual content, and the plaintiff's lack of knowledge "seriously distorts the traditional adversary nature of our legal system's form of dispute resolution." (Id., 484 F.2d at p. 824.) Because of this, the agency must be required provide the requesting party "adequate specificity ... to assure ... proper justification by the governmental agency." (Id. at p. 827.) The D.C. Circuit later clarified that a Vaughn Index required 'a relatively detailed justification, specifically identifying the reasons why a particular exemption is relevant and correlating those claims with the particular part of a withheld document to which they apply.'" (Miccosukee Tribe of Indians of Florida v. U.S. (11th Cir. 2008) 516 F.3d 1235.) In federal circuits that do not require a "Vaughn Index," and also in California courts (see, e.g., State Bd. of Equalization v. Superior Court (1992) 10 Cal.App.4th 1177, 1191-1192), "an adequate factual basis may be established, depending on the circumstances of the case, through affidavits, a Vaughn Index, in camera review, or through a combination of these methods." (Miccosukee Tribe, at p. 1258.) "Because the agency has full knowledge of the contents of the withheld records and the requester has only the agency's affidavits and descriptions of the documents, its affidavits must be specific enough to give the requester 'a meaningful opportunity to contest' the withholding of the documents and the court to determine to determine whether the exemption applies." (Cozen O'Connor, supra, 570 F.Supp.2d at p. 765, citing King v. Dept. of Justice (D.C. Cir. 1987) 830 F.2d 210, 218.) "The agency must describe 'each document or portion thereof withheld, and for each withholding it must discuss the consequences of disclosing the sought-after information.' " (Bay Area Lawyers Alliance for Nuclear Arms Control v. Dept. of State, supra, 818 F.Supp. at p. 1296, quoting King v. Department of Justice, supra, 830 F.2d at p. 224.) Conclusory or boilerplate assertions that merely recite statutory standards are not sufficient.13 (Halpern v. Federal Bureau of Investigation (2d Cir. 1999) 181 F.3d 279, 293; Campbell v. U.S. Dept. of Justice (D.C.Cir 1998) 164 F.3d 20, 30; Cozen O'Connor, supra, 570 F.Supp.2d at p. 765; Natural Resources Defense Counsel v. U.S. Dept. of Defense, supra, 388 F.Supp.2d at p. 1106.) In Church of Scientology of California v. U.S. Dept. of Army (9th Cir. 1979) 611 F.2d 738, "the only statement regarding segregability the IRS made for each withheld document was: 'The document cannot be segregated for partial release.'" (Id. at p. 1162.) As the court stated, the agency "did not explain why the document could not be segregated and released and without this information the Court is unable to determine de novo whether the document can or cannot be segregated." (Ibid.) As stated in a leading treatise, a Vaughn Index or other explanation provided by a defendant agency "fails the nonsegregability test where a blanket declaration that all facts are so intertwined to prevent disclosure under the federal Freedom of Information Act (FOIA) does not constitute a sufficient explanation of non-segregability. Rather, for each entry the defendant is required to 'specify in detail which portions of the document are disclosable and which are allegedly exempt.' The defendants must make such findings for each document. As always, it is incumbent on the agency to prove that no segregable information exists. Without any description of the factual materials contained in the withheld documents, the agency has not satisfied its obligations. The declarations must provide the plaintiff a 'meaningful opportunity to contest, and the district court an adequate foundation to review, the soundness of the withholding.'" (1 O'Reilly, Federal Information Disclosure (June 2011 Supp.) 9:18, p. 456, quoting Wilderness Society v. U.S. Dept. of the Interior (D.D.C. 2004) 344 F.Supp.2d 1 at p. 18.)