BAZELON, Circuit Judge.
Bristol-Myers Company seeks disclosure of certain documents prepared by the Federal Trade Commission (FTC or Commission) in the course of an investigation and administrative enforcement proceeding concerning advertising claims made by manufacturers of nonprescription, internal analgesic drugs. The district court found that the information contained in these documents is protected by exemptions 5 and 7(A) of the Freedom of Information Act, 5 U.S.C. §§ 552(b)(5) and (7)(A) (1976), and granted summary judgment for the FTC. We remand to the district court for further proceedings.
I. BACKGROUND
Bristol-Myers is presently contesting a complaint issued by the FTC in February, 1973, charging that the company has falsely advertised Bufferin, Excedrin, and Excedrin P.M. in violation of sections 5 and 12 of the Federal Trade Commission Act, 15 U.S.C. §§ 45 and 52.1 Pursuant to the Commission’s regulations pertaining to discovery,2 Bristol-Myers has been able to gain access to various studies prepared by or for the FTC concerning consumer awareness and perceptions of analgesics products, and to scientific studies possessed by the FTC concerning the efficacy, speed of action, safety, and side effects of these products. Joint Appendix (J.A.) 121a-125a. Additionally, through resort to FOIA,3 the company has obtained from the Commission 3,160 documents, comprising 31,742 pages, relevant to the charges contained in the complaint. J.A. 114a.
In July, 1976, Bristol-Myers brought suit in the United States District Court for the District of Columbia for disclosure of 1300 documents withheld by the Commission. J.A. 10a-12a. During the course of the district court proceeding, however, the company withdrew its request for a substantial portion of these materials. J.A. 3a-4a, 267a, 283a. Still in dispute are 327 documents, comprising 765 pages. J.A. 4a.
In support of its motion for summary judgment, the Commission filed an indexed description of the information appearing in these 327 documents. J.A. 208a-223a. The index divides the documents into nine cate[22]*22gorfes,4 summarized by the Commission as follows:
CATEGORY A.
Inter-agency memoranda.
CATEGORY B.
100 “Blue Minutes,” i. e., reflections of the Commission’s deliberations.
CATEGORY C.
Documents from Commissioners.
CATEGORY D.
Interview reports (of expert witnesses).
CATEGORY E.
Correspondence between staff and consultants.
CATEGORY F.
One letter discussing a witness’ dissatisfaction with his compensation.
CATEGORY G. .
Drafts and comments (of proposed rules, notice orders, and complaints).
CATEGORY H.
Staff written reports of interviews by counsel.
CATEGORY I.
Memoranda from files of U.S. Pharmocopeial Convention.
The Commission also filed the affidavit of James H. Skiles, an attorney in the FTC’s Bureau of Consumer Protection who has been assigned to the adjudicative proceeding against Bristol-Myers. J.A. 112a-120a. The affidavit explains the Commission’s justifications for invoking exemptions 5 and 7(A) of FOIA.
It was on the basis of the index and accompanying affidavit that the district court granted summary judgment for the Commission.
II. ANALYSIS
The record establishes that the Commission voluntarily disclosed the overwhelming majority of the documents requested. Its index and affidavit, on the whole, describe with particularity the nature and contents of the documents withheld, as required by our decision in Vaughn v. Rosen, 157 U.S. App.D.C. 340, 484 F.2d 820 (1973), cert. denied, 415 U.S. 977, 94 S.Ct. 1564, 39 L.Ed.2d 873 (1974).
The withheld materials can be divided into two broad classes for purposes of analysis. The documents indexed in four Categories, A, B, C, and G, are all said to have been prepared by staff, individual Commissioners, or the Commission itself during the Commission’s process of deciding whether and how to proceed against analgesics manufacturers. Brief for the Commission at 32. The documents indexed in three Categories, D, E, and H, are all said to have been prepared by staff counsel and to contain communications, including interviews, with expert consultants contacted by the Commission during the analgesics investigation. Id.
A. “Predecisional” Memoranda
The district court found that the documents indexed in Categories A, B, C, and G are shielded from disclosure by exemption 5. This exemption permits an agency to withhold “inter-agency or intra-agency memorandums or letters which would not be available by law to a party other than an agency in litigation with the agency.” 5 U.S.C. § 552(b)(5).
The Commission contends that this result was correct insofar as Categories A, C and G are concerned because these memoranda are communications between and among FTC staff and Commissioners containing “advice, recommendations, opinions, analyses of potential trial or rule-making strategy and evaluations of evidence.” J.A. 114a.5 Relying on the Supreme Court’s decisions in Renegotiation Board v. Grumman Aircraft, 421 U.S. 168, 95 S.Ct. 1491, 44 L.Ed.2d 57 (1965) and NLRB v. Sears, Roe[23]*23buck & Co., 421 U.S. 132, 95 S.Ct. 1504, 44 L.Ed.2d 29 (1965), as well as our decision in Sterling Drug, Inc. v. FTC, 146 U.S.App. D.C. 237, 450 F.2d 698 (1971), the Commission argues that these documents are thus “predecisional” in character and must be protected in order to “prevent injury to the quality of agency decisions.” Brief for the Commission at 19-20 (quoting Sears, supra, 421 U.S. at 151, 95 S.Ct. 1516). The Commission contends that the documents listed in Category B — its so-called “Blue Minutes” —are similarly exempt as deliberative material under our decision in Ash Grove Cement Co. v. FTC, 167 U.S.App.D.C. 249, 250, 511 F.2d 815, 816, rehearing denied, 171 U.S.App.D.C. 285, 519 F.2d 934 (1975).
Bristol-Myers, on the other hand, urges that the documents indexed in these Categories may be subject to the affirmative disclosure and indexing requirements of FOIA contained in 5 U.S.C. § 552(a)(2). These requirements apply to “final opinions made in the adjudication of cases,” § 552(a)(2)(A), to “statements of policy and interpretations which have been adopted by the agency,” § 552(a)(2)(B), and to “instructions to staff that affect a member of the public,” § 552(a)(2)(C).
The interplay of exemption 5 with the affirmative provisions of FOIA on which Bristol-Myers relies presents a comparatively new issue, which the Supreme Court discussed in NLRB v. Sears, Roebuck & Co., supra. Before examining that case, however, we discuss briefly the development of principles governing exemption 5.
It is well-established that, among other purposes, exemption 5 was intended by Congress to protect “the consultative functions of government . . . Sears, supra, 421 U.S. at 149, 95 S.Ct. 1491 (quoting Kaiser Aluminum & Chemical Corp. v. United States, 157 F.Supp. 939, 946, 141 Ct.Cl. 38, 49 (1958). See also EPA v. Mink, 410 U.S. 73, 86, 93 S.Ct. 827, 35 L.Ed.2d 119 (1973). S.Rep.No.813, 89th Cong., 2d Sess., 9 (1966) (hereinafter S.Rep. No.813); H.R.Rep.No.1497, 89th Cong., 2d Sess. 10 (1966) (hereinafter H.R.Rep.No. 1497), U.S.Code Cong. & Admin.News 1966, p. 2418. Such protection extends generally to documents “reflecting advisory opinions, recommendations and deliberations comprising part of a process by which governmental decisions and policies are formulated.” Id. 421 U.S. at 150, 95 S.Ct. at 1516 (quoting Carl Zeiss Stiftung v. V.E.B. Carl Zeiss, Jena, 40 F.R.D. 318, 324 (D.D.C.1966), aff’d per curiam, 128 U.S.App.D.C. 10, 384 F.2d 979, cert. denied, 389 U.S. 952, 88 S.Ct. 334, 19 L.Ed.2d 361 (1967)). Such protection was deemed necessary by Congress, the Senate Report explains, because “it would be impossible to have any frank discussion of legal or policy matters in writing if all such writings were to be subjected to public scrutiny.” S.Rep.No.813, supra, at 9. See also United States v. Nixon, 418 U.S. 683, 705, 94 S.Ct. 3090, 3106, 41 L.Ed.2d 1039 (1974) (“Human experience teaches that those who expect public dissemination of their remarks may well temper candor with a concern for appearances and for their own interests to the detriment of the decision-making process.”).
In seeking to implement this congressional mandate, courts have established the general principle that predecisional memoranda are privileged,6 while postdecisional memoranda — communications designed to explain a decision already made — are not.7
The Supreme Court recognized in Sears, however, that “the line between predecisional documents and postdecisional docu[24]*24merits may not always be a bright one. Indeed, even the prototype of the postdecisional document — the ‘final opinion’ — serves the dual function of explaining the decision just made and providing guides for decisions of similar or analogous cases in the future.” 421 U.S. at 152 n. 19, 95 S.Ct. at 1517.
Two aspects of the Court’s holding in Sears are material to our analysis here. First, the Court ruled that Advice and Appeals Memoranda prepared by the General Counsel for the National Labor Relations Board (NLRB) deciding not to issue a complaint must be disclosed under FOIA.8 Although the NLRB urged that these memoranda were predecisional, the Court held exemption 5 inapplicable. It based this conclusion both on the affirmative disclosure and indexing requirements contained in 5 U.S.C. § 552(a)(2) and on considerations of congressional policy underlying FOIA. In the context of the practical realities of the NLRB’s decision-making process, the Court reasoned, Advice and Appeals Memoranda directing that a charge be dismissed constitute “final opinions” made in the “adjudication of cases.”9 Such documents are therefore covered, irrespective of any predecisional character, by 5 U.S.C. § 552(a)(2)(A). 421 U.S. at 157-159, 95 S.Ct. 1504. The court refused to construe exemption 5 to protect documents covered by this provision, since this “affirmative portion of the Act . . represents a strong congressional aversion to ‘secret [agency] law’ . . . and represents an affirmative congressional purpose to require disclosure of documents which have ‘the force and effect of law.’ ” 10 421 U.S. at 153, 95 S.Ct. at 1518 (citations omitted).
Second, the Court held in Sears that a memorandum prepared prior to the decision to dismiss a charge will lose its predecisional character if the agency chooses expressly to adopt or incorporate it by reference in a “final opinion.” 11 Id. at 161, 95 S.Ct. at 1521. The Court explained:
The probability that an agency employee will be inhibited from freely advising a decisionmaker for fear that his advice, if adopted, will become public is slight. First, when adopted, the reasoning becomes that of agency and becomes its responsibility to defend. Second, agency employees will generally be encouraged rather than discouraged by public knowl[25]*25edge that their policy suggestions have been adopted by the agency. Moreover, the public interest in knowing the reasons for a policy actually adopted by an agency supports . . . [disclosure].
Id. (emphasis in original).
Bristol-Myers contends that certain decisions reached by the Commission during the course of the analgesics investigation constitute “final action by the agency” under Sears and that those memoranda indexed in Categories A, B, C, and G which explain the Commission’s reasons for such action cannot now be regarded as predecisional. Brief for Appellant at 5-10, 14-19. Specifically, Bristol-Myers seeks disclosure of any documents containing the Commission’s reasons for (a) choosing not to proceed by rulemaking against the over-the-counter analgesics industry as a whole, (b) terminating a prior adjudicatory proceeding against Bristol-Myers, and (e) choosing not to include certain proposed allegations in the complaint presently pending.12
The district court held, however, that Sears has no application in this case because the Supreme Court “carefully confined [its] holding ... to the unique structure of the [NLRB].” District Court Opinion at 3 n. 6, J.A. 4a. We disagree. It appears to .us that the Court meant in Sears to establish as a general principle that action taken by the responsible decisionmaker in an agency’s decision-making process which has the practical effect of disposing of a matter before the agency is “final” for purposes of FOIA. If such action is accompanied by a written explanation of the decisionmaker’s reasoning, that explanation constitutes a “final opinion” and must be disclosed. Thus, the Court explained its analysis in the language of the Administrative Procedure Act generally:
The decision [by General Counsel] to dismiss a charge is a decision in a “case” and constitutes an “adjudication”: an “adjudication” is defined under the Administrative Procedure Act ... as “agency process for the formulation of an order,” 5 U.S.C. § 551(7); an “order” is defined as “the whole or a part of a final disposition, whether affirmative [or] negative . . of an agency in a matter . . .,”5 U.S.C. § 551(6) (emphasis added); . . Since an Advice or Appeals Memorandum explains the reasons for the “final disposition” it plainly qualifies as an “opinion”; and falls within 5 U.S.C. § 552(a)(2)(A).
Id. at 158-159, 95 S.Ct. at 1520.
In the FTC’s administrative process, the Commission itself is responsible for decisions analogous to those made in Sears by General Counsel for the NLRB. The Commission’s brief, at 30, makes this clear: “The Commission is invested by law with the authority to issue complaints (15 U.S.C. [§] 45), and while the Commission has delegated authority to various subordinate units, like the Bureau of Consumer Protection, the Commission retains final authority as to whether any complaint shall issue and the content of any issued complaint. 16 C.F.R. [§§] 0.16, 3.11. Similarly, the Commission must authorize any rulemaking action.” In this case, then, a decision by the Commission itself to terminate an adjudicatory proceeding or not to include a proposed charge in a complaint is a “decision in a ‘ease’ and constitutes an ‘adjudication’ . [of] ‘the whole or a part of ... a matter’ ” before the agency. If the Commission prepared a memorandum explaining the reasons for the decision, it would qualify as a “final opinion” and be subject to indexing and disclosure under 5 U.S.C. § 552(a)(2)(A). Similarly, a decision not to [26]*26proceed by rulemaking would also be a “final” one for purposes of FOIA. If such a decision were accompanied by a statement of reasons, the statement would be covered under 5 U.S.C. § 552(a)(2)(B) (“statements of policy and interpretations which have been adopted by the agency”) or § 552(a)(2)(C) (“instructions to staff that affect a member of the public”).13
It is unclear on this record, however, whether the Commission itself ever prepared any memoranda explaining its basis for these decisions. As noted earlier, the Commission says that the documents written by staff and individual Commissioners (Categories A, C, and G) were prepared for purposes of discussion. And the so-called “Blue Minutes” (Category B) are said to be merely “reflections of the Commission’s deliberations.” The Commission was not required under FOIA to prepare memoranda explaining its decisions. Renegotiation Board v. Grumman Aircraft, 421 U.S. 168, 192, 95 S.Ct. 1491, 44 L.Ed.2d 57 (1975); Mead Data Central, Inc. v. United States Department of the Air Force (Mead Data II), 188 U.S.App.D.C. 51 at 54, 575 F.2d 932 at 935 (1978). And if it chose not to do so, we could not determine whether the reasons underlying its decision were identical to those in the documents prepared by staff and individual Commissioners for its consideration. Grumman, supra, 421 U.S. at 192, 95 S.Ct. 1491; Mead Data II, supra, 188 U.S.App.D.C. at 55, 575 F.2d at 936; Kent Corp. v. NLRB, 530 F.2d 610 at 619-620; Sterling Drug, Inc. v. FTC, supra, 146 U.S. App.D.C. at 244-245, 450 F.2d at 705-708. At best, Bristol-Myers could argue that these documents might contain the reasons underlying the Commission’s actions. In such circumstances the Supreme Court has made it clear that disclosure would violate exemption by impinging on the agency’s predecisional processes. Grumman, supra, 421 U.S. at 192, 95 S.Ct. 1491.
We are troubled, however, by the ambiguity in the record concerning the nature and contents of the Commission’s “Blue Minutes.” The index provides only the following description of Category B: “Over 100 so-called ‘blue minutes’ or reflections of the Commission’s deliberations.” J.A. 216a. Evidently, the Commission simply assumed that these minutes are per se protected under our decision in Ash Grove Cement Co. v. FTC, 167 U.S.App.D.C. 249, 511 F.2d 815, rehearing denied, 171 U.S. App.D.C. 285, 519 F.2d 934 (1975), and therefore decided that additional detail was unnecessary. At oral argument, counsel for the Commission indicated that this was the case and acknowledged that the minutes [27]*27could have been described with greater particularity if that were required.
We think that both the Commission and the district court14 read too much into our decision in Ash Grove. In that case, two types of “minutes” were at issue. First, the “Blue Minutes” were described there as “staff directives,” 167 U.S.App.D.C. at 250, 511 F.2d at 816, not as “reflections of the Commission’s deliberations.”15 These “staff directives” were held to be protected by exemptions 5 and 7. Id. Whether such directives may be withheld after Sears is a question we need not decide.16 Second, the Commission had withheld its so-called “chronological minutes,” described as
accounts of the Commissioner’s executive meetings and conferences . . . the deliberations of the Commission such as exchange of opinions between individual Commissioners, their recommendations, motions, discussions and statements. They also contain staff recommendations and involve pending cases, internal reorganization procedures, personnel actions, policy determinations and generally reflect the Commission’s decision-making process.
Id. 167 U.S.App.D.C. at 251, 511 F.2d at 817 (emphasis supplied by the court). The court held that the one-paragraph description of the chronological minutes was conclusory under the standards established by our pri- or decisions17 and that the portions of these minutes which contain policy determinations were subject to disclosure. It directed the district court on remand to examine at least a representative portion of the minutes in camera before determining whether or not exemption 5 applied. Id. 167 U.S. App.D.C. at 252, 511 F.2d at 818.
It would appear that the “Blue Minutes” at issue in this case are akin to the “chronological minutes” involved in Ash Grove. Thus, before applying exemption 5 to the Blue Minutes, the district court should have ascertained whether they contain “policy determinations” within the meaning of Ash Grove.18 The district court did not address this question, and certainly could not have resolved it on the basis of the description supplied by the Commission.
The district court should also have addressed the question whether any information in the “Blue Minutes” qualifies as “final opinions . . made in the adju[28]*28dication of cases” within the meaning of Sears. If so, such opinions are subject not only to disclosure but also to the affirmative indexing requirement contained in 5 U.S.C. § 552(a)(2)(A). Similarly, it must be determined whether the minutes contain matters covered by §§ 552(a)(2)(B) and (C).19 Moreover, the possibility that the “Blue Minutes” may contain policy matters raises the question whether the Commission has adopted or incorporated by reference the reasoning contained in any of the documents prepared by staff or individual Commissioners for its consideration.20 If so, these documents, too, would lose their predecisional character and fall outside the scope of exemption 5.21
B. Memoranda Reflecting Communications with Expert Consultants
The district court found that the documents listed in Categories D, E, and H are also shielded from disclosure by exemption 5, but on a different rationale. The court held that these documents are exempted as attorney “work product.”
It is well-established that exemption 5 was designed also to protect the work product of agency attorneys. NLRB v. Sears, Roebuck & Co., supra, 421 U.S. at 154-155, 95 S.Ct. 1504. See also S.Rep.No.813, supra, at 2.
The fundamental principles underlying contemporary understanding of the work product doctrine derive from Hickman v. Taylor, 329 U.S. 495, 67 S.Ct. 385, 90 L.Ed. 1645 (1947). There the Court said, in pertinent part:
In performing his various duties, however, it is essential that a lawyer work with a certain degree of privacy, free from unnecessary intrusion by opposing parties and their counsel. Proper presentation of a client’s case demands that he assemble information, sift what he considers to be the relevant from the irrelevant facts, prepare his legal theories and plan his strategy without undue and needless interference. . . . This work is reflected, of course, in interviews, statements, memoranda, correspondence, briefs, mental impressions, personal beliefs, and countless other tangible and intangible ways — aptly though roughly termed by the Circuit Court of Appeals in this case as the “work product of the lawyer.” Were such materials open to opposing counsel on mere demand, much of what is now put down in writing would remain unwritten. . . . Inefficiency, unfairness and sharp practices would inevitably develop in the giving of legal advice and in the preparation of cases for trial.
Id. at 511, 67 S.Ct. at 393.
We do not suggest, of course, that the mere fact that an agency document was prepared by an attorney necessarily qualifies it as “work product.” “The executive branch of our government employs an uncountable and ever-growing number of attorneys, and [exemption 5 of the FOIA] can hardly be understood as protecting everything they put on paper.” Kent Corp. v. NLRB, 530 F.2d 612, 623 (5th Cir. 1976). Also, we recognize that this doctrine is not without its difficulties and many exceptions. See generally 8 Wright & Miller, Federal Practice and Procedures §§ 2021-2028 (1976). As the Supreme [29]*29Court has said, however, “[w]hatever the outer boundaries of the attorney’s work-product rule are, the rule clearly applies to memoranda prepared by an attorney in contemplation of litigation which sets forth the attorney’s theory of the case and his litigation strategy.” NLRB v. Sears, Roebuck & Co., supra, 421 U.S. at 154, 95 S.Ct. at 1518.
The record establishes that the documents listed in two categories, D and E, fall well within the rule. First, as noted earlier, these memoranda were prepared by staff counsel for the Commission. J.A. 116a-117a. Second, they were prepared specifically for purposes of the analgesics cases. Id. Indeed, the index reveals that a substantial number of these documents were prepared by staff counsel after the complaint was issued against Bristol-Myers. J.A. 218a-220a. Finally, the affidavit states: “[T]he documents described in Categories D and E go to the very heart of complaint counsel’s cases because they contain staff [counsel’s] non-verbatim reports of interviews or conversations which, questions asked of, responses given by and correspondence with our expert consultants. In addition, they contain discussions as to the strengths and weaknesses of certain tests, studies and theories which both support and conceivably work against the Commission’s allegations, as well as the staff’s analysis of a particular expert’s expertise.” J.A. 116a-117a.
The documents in the third category, Category H, present a slightly different case, but we think the district court was nevertheless correct in concluding that they, too, are work product. These memoranda are notes taken by Commission counsel during “pre-trial discovery interviews of complaint counsel’s expert witnesses conducted by attorneys for . . . American Home,” another respondent in the analgesics cases. J.A. 119a. Since attorneys for the Commission posed no questions during these interviews, it cannot be said that the interviews themselves reveal the legal theories or trial strategy of Commission counsel. It is clear, however, that the notes were prepared by Commission counsel in contemplation of litigation, and we think the district court could properly accept the Commission’s position that disclosure of such notes would reveal counsel’s “mental impressions” and evaluations of the testimony given.
Bristol-Myers appears to concede that the work-product rule would ordinarily apply here but urges that we should take account of the company’s particular need for the information these documents contain. FOIA, however, does not distinguish between litigants on the basis of their need for information. The House Report indicates that exemption 5 was intended to permit agencies to withhold intra-agency memoranda which would not “routinely be disclosed” in private litigation.22 H.R.Rep. No.1497, supra, at 10. See also Sears, supra, 421 U.S. at 149 n. 16, 95 S.Ct. 1504; Sterling Drug, Inc. v. FTC, 146 U.S.App. D.C. 244, 250-251, 450 F.2d 698, 704-705 (1971).
Although we thus agree with the district court that the documents in these categories are work product, it does not necessarily follow that they may be withheld. Sears makes it clear that such memoranda lose thj protection of exemption 5 to the extent that they have been incorporated by reference in a nonexempt “final opinion.”23 421 U.S. at 154, 161, 95 S.Ct. 1504.
[30]*30C. Exemption 7(A)
There would be no need for further proceedings, of course, if the “Blue Minutes” and any memoranda they may incorporate by reference would be protected in any event by exemption 7(A). This is the Commission’s alternate contention, resolved for the most part against it in district court24 and pressed again on appeal. We note that the Supreme Court left open in Sears the question whether exemption 7 applies to Advice and Appeals Memoranda deciding not to issue a complaint. 421 U.S. at 162-163, 95 S.Ct. 1504. The Court did rule, however, that a document protected by exemption 7 does not become disclosable solely because it is incorporated by reference in a “final opinion.” Id. at 166, 95 S.Ct. 1504.
Without greater knowledge of the contents of the Blue Minutes and the purposes they are designed to serve, we cannot determine whether exemption 7(A) applies. This exemption, as amended in 1974,25 protects “investigatory records compiled for law enforcement purposes, but only to the extent that the production of such records would (A) interfere with enforcement proceedings . .” Although minutes or “reflections” of the Commission’s deliberations would appear to be something other than [31]*31“investigatory records,”26 we are reluctant to make this determination without more elucidation.
Similarly, there would be no point in our speculating about whether any documents that might be incorporated by reference in the Blue Minutes would qualify for nondisclosure under this exemption. Even assuming such documents were “investigatory records,” the Commission would be required to demonstrate that release of the particular information they contain would “interfere with enforcement proceedings.”27 Such determinations should be made by the district court in the first instance on the basis of evidence supplied by the Commission.
III. CONCLUSION
In accordance with our decision in Ash Grove, supra, the ease must be remanded to the district court for in camera inspection of at least a representative sample of the “Blue Minutes” (Category B) to determine whether any portion of these minutes is disclosable under the principles outlined in this opinion, and, if so, for findings as to whether any other documents at issue are disclosable by reason of incorporation by reference. The district court may, if so advised, take additional evidence to determine whether exemption 7(A) applies to these materials.
So ordered.