(Slip Opinion)              OCTOBER TERM, 2010                                       1

                                       Syllabus

         NOTE: Where it is feasible, a syllabus (headnote) will be released, as is
       being done in connection with this case, at the time the opinion is issued.
       The syllabus constitutes no part of the opinion of the Court but has been
       prepared by the Reporter of Decisions for the convenience of the reader.
       See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337.


SUPREME COURT OF THE UNITED STATES

                                       Syllabus

           MILNER v. DEPARTMENT OF THE NAVY

CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR
                  THE NINTH CIRCUIT

   No. 09–1163. Argued December 1, 2010—Decided March 7, 2011
The Freedom of Information Act (FOIA) requires federal agencies to
  make Government records available to the public, subject to nine ex
  emptions. This case concerns Exemption 2, which protects from dis
  closure material “related solely to the internal personnel rules and
  practices of an agency.” 5 U. S. C.§552(b)(2). This provision replaced
  an Administrative Procedure Act (APA) exemption for “any matter
  relating solely to the internal management of an agency,” 5 U. S. C.
  §1002 (1964 ed.). Congress believed that the “sweep” of the phrase
  “internal management” had led to excessive withholding, and drafted
  Exemption 2 “to have a narrower reach.” Department of Air Force v.
  Rose, 425 U. S. 352, 362–363.
    In Rose, the Court found that Exemption 2 could not be invoked to
  withhold Air Force Academy honor and ethics hearing summaries.
  The exemption, the Court suggested, primarily targets material con
  cerning employee relations or human resources. But the Court stated
  a possible caveat: That understanding of the provision’s coverage
  governed “at least where the situation is not one where disclosure
  may risk circumvention of agency regulation.” Id., at 369. The D. C.
  Circuit subsequently converted this caveat into a new definition of
  Exemption 2’s scope, finding that the exemption also covered any
  “predominantly internal” materials whose disclosure would “signifi
  cantly ris[k] circumvention of agency regulation or statutes.” Crooker
  v. Bureau of Alcohol, Tobacco & Firearms, 670 F. 2d 1051, 1056–
  1057, 1074. Courts now use the term “Low 2” for human resources
  and employee relations records and “High 2” for records whose disclo
  sure would risk circumvention of the law.
    Petitioner Milner submitted FOIA requests for explosives data and
  maps used by respondent Department of the Navy (Navy or Govern
2                MILNER v. DEPARTMENT OF NAVY

                                Syllabus

    ment) in storing munitions at a naval base in Washington State.
    Stating that disclosure would threaten the security of the base and
    surrounding community, the Navy invoked Exemption 2 and refused
    to release the data. The District Court granted the Navy summary
    judgment, and the Court of Appeals affirmed, relying on the High 2
    interpretation.
Held: Because Exemption 2 encompasses only records relating to em
 ployee relations and human resources issues, the explosives maps
 and data requested here do not qualify for withholding under that
 exemption. Pp. 6–19.
    (a) Exemption 2 shields only those records relating to “personnel
 rules and practices.” When used as an adjective in this manner, the
 key statutory word “personnel” refers to human resources matters.
 For example, a “personnel department” deals with employee prob
 lems and interviews applicants for jobs. FOIA Exemption 6 provides
 another example, protecting certain “personnel . . . files” from disclo
 sure. §552(b)(6). “[T]he common and congressional meaning of . . .
 ‘personnel file’ ” is a file maintained by a human resources office col
 lecting personal information about employees, such as examination
 results and work performance evaluations. Rose, supra, at 377. Ex
 emption 2 uses “personnel” in the exact same way. An agency’s “per
 sonnel rules and practices” all share a critical feature: They concern
 conditions of employment in federal agencies—such matters as hiring
 and firing, work rules and discipline, compensation and benefits.
 These items currently fall within the so-called Low 2 exemption. And
 under this Court’s construction of the statutory language, Low 2 is all
 of 2.
    FOIA’s purpose reinforces this reading. The statute’s goal is
 “broad disclosure,” and the exemptions must be “given a narrow com
 pass.” Department of Justice v. Tax Analysts, 492 U. S. 136, 151. A
 narrow construction stands on especially firm footing with respect to
 Exemption 2, which was intended to hem in the expansive withhold
 ing that occurred under the prior APA exemption for “internal man
 agement” records.
    Exemption 2, as interpreted here, does not reach the requested ex
 plosives information. The data and maps, which calculate and visu
 ally portray the magnitude of hypothetical detonations, in no way re
 late to “personnel rules and practices,” as that term is most naturally
 understood. Pp. 6–10.
    (b) The Government’s two alternative readings of Exemption 2
 cannot be squared with the statute. Pp. 10–17.
    (c) While the Navy has a strong security interest in shielding the
 explosives data and maps from public disclosure, the Government
 has other tools at hand to protect such information: FOIA Exemption
                     Cite as: 562 U. S. ____ (2011)                    3

                                Syllabus

  1 prevents access to classified documents; Exemption 3 applies to re-
  cords that any other statute exempts from disclosure; and Exemption
  7 protects “information compiled for law enforcement purposes” if its
  release, inter alia, “could reasonably be expected to endanger the life
  or physical safety of any individual,” §552(b)(7)(F). The Navy’s ar-
  gument that the explosives information is exempt under Exemption 7
  remains open for the Ninth Circuit to address on remand. And if
  these or other exemptions do not cover records whose release would
  threaten the Nation’s vital interests, the Government may of course
  seek relief from Congress. Pp. 17–18.
575 F. 3d 959, reversed and remanded.

  KAGAN, J., delivered the opinion of the Court, in which ROBERTS,
C. J., and SCALIA, KENNEDY, THOMAS, GINSBURG, ALITO, and SOTOMAYOR,
JJ., joined. ALITO, J., filed a concurring opinion. BREYER, J., filed a
dissenting opinion.
                       Cite as: 562 U. S. ____ (2011)                              1

                            Opinion of the Court

    NOTICE: This opinion is subject to formal revision before publication in the
    preliminary print of the United States Reports. Readers are requested to
    notify the Reporter of Decisions, Supreme Court of the United States, Wash
    ington, D. C. 20543, of any typographical or other formal errors, in order
    that corrections may be made before the preliminary print goes to press.


SUPREME COURT OF THE UNITED STATES
                                  _________________

                                  No. 09–1163
                                  _________________


GLEN SCOTT MILNER, PETITIONER v. DEPARTMENT
               OF THE NAVY
 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF

            APPEALS FOR THE NINTH CIRCUIT

                                [March 7, 2011]


  JUSTICE KAGAN delivered the opinion of the Court.
  The Freedom of Information Act (FOIA), 5 U. S. C. §552,
requires federal agencies to make Government records
available to the public, subject to nine exemptions for
specific categories of material. This case concerns the
scope of Exemption 2, which protects from disclosure
material that is “related solely to the internal personnel
rules and practices of an agency.” §552(b)(2). Respondent
Department of the Navy (Navy or Government) invoked
Exemption 2 to deny a FOIA request for data and maps
used to help store explosives at a naval base in Washing
ton State. We hold that Exemption 2 does not stretch so
far.
                           I
  Congress enacted FOIA to overhaul the public
disclosure section of the Administrative Procedure Act
(APA), 5 U. S. C. §1002 (1964 ed.). That section of the
APA “was plagued with vague phrases” and gradually
became more “a withholding statute than a disclosure
statute.” EPA v. Mink, 410 U. S. 73, 79 (1973). Congress
intended FOIA to “permit access to official information
2            MILNER v. DEPARTMENT OF NAVY

                     Opinion of the Court

long shielded unnecessarily from public view.” Id., at 80.
FOIA thus mandates that an agency disclose records on
request, unless they fall within one of nine exemptions.
These exemptions are “explicitly made exclusive,” id., at
79, and must be “narrowly construed,” FBI v. Abramson,
456 U. S. 615, 630 (1982).
  At issue here is Exemption 2, which shields from com
pelled disclosure documents “related solely to the internal
personnel rules and practices of an agency.” §552(b)(2).
Congress enacted Exemption 2 to replace the APA’s ex
emption for “any matter relating solely to the internal
management of an agency,” 5 U. S. C. §1002 (1964 ed.).
Believing that the “sweep” of the phrase “internal man
agement” had led to excessive withholding, Congress
drafted Exemption 2 “to have a narrower reach.” Depart
ment of Air Force v. Rose, 425 U. S. 352, 362–363 (1976).
  We considered the extent of that reach in Department of
Air Force v. Rose. There, we rejected the Government’s
invocation of Exemption 2 to withhold case summaries of
honor and ethics hearings at the United States Air Force
Academy. The exemption, we suggested, primarily targets
material concerning employee relations or human re
sources: “use of parking facilities or regulations of lunch
hours, statements of policy as to sick leave, and the like.”
Id., at 363 (quoting S. Rep. No. 813, 89th Cong., 1st Sess.,
8 (1965) (hereinafter S. Rep.)); see Rose, 425 U. S., at 367.
“[T]he general thrust” of Exemption 2, we explained, “is
simply to relieve agencies of the burden of assembling and
maintaining [such information] for public inspection.” Id.,
at 369. We concluded that the case summaries did not fall
within the exemption because they “d[id] not concern only
routine matters” of “merely internal significance.” Id., at
370. But we stated a possible caveat to our interpretation
of Exemption 2: That understanding of the provision’s
coverage governed, we wrote, “at least where the situation
                     Cite as: 562 U. S. ____ (2011)                   3

                         Opinion of the Court

is not one where disclosure may risk circumvention of
agency regulation.” Id., at 369.
   In Crooker v. Bureau of Alcohol, Tobacco & Firearms,
670 F. 2d 1051 (1981), the D. C. Circuit converted this
caveat into a new definition of Exemption 2’s scope.
Crooker approved the use of Exemption 2 to shield a man
ual designed to train Government agents in law enforce
ment surveillance techniques. The D. C. Circuit noted
that it previously had understood Exemption 2 to “refe[r]
only to ‘pay, pensions, vacations, hours of work, lunch
hours, parking, etc.’ ” Id., at 1056 (quoting Jordan v.
Department of Justice, 591 F. 2d 753, 763 (1978)). But the
court now thought Exemption 2 should also cover any
“predominantly internal” materials,1 Crooker, 670 F. 2d,
at 1056–1057, whose disclosure would “significantly ris[k]
circumvention of agency regulations or statutes,” id., at
1074. This construction of Exemption 2, the court rea
soned, flowed from FOIA’s “overall design,” its legislative
history, “and even common sense,” because Congress could
not have meant to “enac[t] a statute whose provisions
undermined . . . the effectiveness of law enforcement
agencies.” Ibid.
   In the ensuing years, three Courts of Appeals adopted
the D. C. Circuit’s interpretation of Exemption 2. See 575
F. 3d 959, 965 (CA9 2009) (case below); Massey v. FBI, 3
F. 3d 620, 622 (CA2 1993); Kaganove v. EPA, 856 F. 2d
884, 889 (CA7 1988).2 And that interpretation spawned a
——————
  1 The court adopted the “predominantly internal” standard as a way

of implementing the exemption’s requirement that materials “relat[e]
solely to” an agency’s internal personnel rules and practices. The
word “solely,” the court reasoned, “has to be given the construction,
consonant with reasonableness, of ‘predominantly’ ” because otherwise
“solely” would conflict with the expansive term “related.” 670 F. 2d, at
1056 (some internal quotation marks omitted).
  2 Three other Courts of Appeals had previously taken a narrower view

of Exemption 2’s scope, consistent with the interpretation adopted in
4               MILNER v. DEPARTMENT OF NAVY

                         Opinion of the Court

new terminology: Courts applying the Crooker approach
now refer to the “Low 2” exemption when discussing mate
rials concerning human resources and employee relations,
and to the “High 2” exemption when assessing records
whose disclosure would risk circumvention of the law.
See, e.g., 575 F. 3d, at 963; Schiller v. NLRB, 964 F. 2d
1205, 1208 (CADC 1992). Congress, as well, took notice of
the D. C. Circuit’s decision, borrowing language from
Crooker to amend Exemption 7(E) when next enacting
revisions to FOIA. The amended version of Exemption
7(E) shields certain “records or information compiled for
law enforcement purposes” if their disclosure “could rea
sonably be expected to risk circumvention of the law.”
§552(b)(7)(E); see Freedom of Information Reform Act of
1986, §1802(a), 100 Stat. 3207–49.
                           II
   The FOIA request at issue here arises from the Navy’s
operations at Naval Magazine Indian Island, a base in
Puget Sound, Washington. The Navy keeps weapons,
ammunition, and explosives on the island. To aid in the
storage and transport of these munitions, the Navy uses
data known as Explosive Safety Quantity Distance
(ESQD) information. 575 F. 3d, at 962. ESQD informa
tion prescribes “minimum separation distances” for explo
sives and helps the Navy design and construct storage
——————
Rose. See Cox v. Department of Justice, 576 F. 2d 1302, 1309–1310
(CA8 1978) (concluding that Exemption 2 covers only an agency’s
internal “housekeeping matters” (internal quotation marks omitted));
Stokes v. Brennan, 476 F. 2d 699, 703 (CA5 1973) (holding that Exemp
tion 2 “must not be read so broadly as to exempt” an Occupational
Safety and Health Administration manual for training compliance
officers); Hawkes v. IRS, 467 F. 2d 787, 797 (CA6 1972) (“[T]he internal
practices and policies referred to in [Exemption 2] relate only to . . .
employee-employer type concerns”). These Circuits have never revised
their understandings of the exemption. See infra, at 13, n. 7.
                     Cite as: 562 U. S. ____ (2011)                     5

                          Opinion of the Court

facilities to prevent chain reactions in case of detonation.
Ibid. The ESQD calculations are often incorporated into
specialized maps depicting the effects of hypothetical
explosions. See, e.g., App. 52.
  In 2003 and 2004, petitioner Glen Milner, a Puget
Sound resident, submitted FOIA requests for all ESQD
information relating to Indian Island. 575 F. 3d, at 962.
The Navy refused to release the data, stating that disclo
sure would threaten the security of the base and surround
ing community. In support of its decision to withhold the
records, the Navy invoked Exemption 2. Ibid.3
  The District Court granted summary judgment to the
Navy, and the Court of Appeals affirmed, relying on the
High 2 interpretation developed in Crooker. 575 F. 3d, at
963. The Court of Appeals explained that the ESQD
information “is predominantly used for the internal pur
pose of instructing agency personnel on how to do their
jobs.” Id., at 968. And disclosure of the material, the
court determined, “would risk circumvention of the law”
by “point[ing] out the best targets for those bent on wreak
ing havoc”—for example, “[a] terrorist who wished to hit
the most damaging target.” Id., at 971. The ESQD infor
mation, the court concluded, therefore qualified for a High
2 exemption. 575 F. 3d, at 971.
  We granted certiorari in light of the Circuit split re
specting Exemption 2’s meaning, 561 U. S. ___ (2010), and
we now reverse.

——————
  3 The Navy also invoked Exemption 7(F), which applies to “records or
information compiled for law enforcement purposes, but only to the
extent that the production of such . . . records . . . could reasonably be
expected to endanger the life or physical safety of any individual.” 5
U. S. C. §552(b)(7)(F). The courts below did not decide whether the
Navy could withhold the ESQD data under that exemption. 575 F. 3d
959, 971, n. 8 (CA9 2009); No. CV–06–01301 (WD Wash., Oct. 30, 2007),
App. to Pet. for Cert. 4, 25, 2007 WL 3228049, *8.
6             MILNER v. DEPARTMENT OF NAVY 


                      Opinion of the Court 


                              III 

   Our consideration of Exemption 2’s scope starts with its
text. See, e.g., Park ’N Fly, Inc. v. Dollar Park & Fly, Inc.,
469 U. S. 189, 194 (1985) (“Statutory construction must
begin with the language employed by Congress and the
assumption that the ordinary meaning of that language
accurately expresses the legislative purpose”). Judicial
decisions since FOIA’s enactment have analyzed and
reanalyzed the meaning of the exemption. But compara
tively little attention has focused on the provision’s 12
simple words: “related solely to the internal personnel
rules and practices of an agency.”
   The key word in that dozen—the one that most clearly
marks the provision’s boundaries—is “personnel.” When
used as an adjective, as it is here to modify “rules and
practices,” that term refers to human resources matters.
“Personnel,” in this common parlance, means “the selec
tion, placement, and training of employees and . . . the
formulation of policies, procedures, and relations with [or
involving] employees or their representatives.” Webster’s
Third New International Dictionary 1687 (1966) (hereinaf
ter Webster’s). So, for example, a “personnel department”
is “the department of a business firm that deals with
problems affecting the employees of the firm and that
usually interviews applicants for jobs.” Random House
Dictionary 1075 (1966) (hereinafter Random House).
“Personnel management” is similarly “the phase of man
agement concerned with the engagement and effective
utilization of manpower to obtain optimum efficiency of
human resources.” Webster’s 1687. And a “personnel
agency” is “an agency for placing employable persons in
jobs; employment agency.” Random House 1075.
   FOIA itself provides an additional example in Exemp
tion 6. See Ratzlaf v. United States, 510 U. S. 135, 143
(1994) (“A term appearing in several places in a statutory
                   Cite as: 562 U. S. ____ (2011)                 7

                        Opinion of the Court

text is generally read the same way each time it appears”).
That exemption, just a few short paragraphs down from
Exemption 2, protects from disclosure “personnel and
medical files and similar files the disclosure of which
would constitute a clearly unwarranted invasion of per
sonal privacy.” §552(b)(6). Here too, the statute uses the
term “personnel” as a modifier meaning “human re
sources.” See Tr. of Oral Arg. 32 (“[The Court:] It’s [an]
H. R. file, right? [The Government:] That’s generally
true”). As we recognized in Rose, “the common and con
gressional meaning of . . . ‘personnel file’ ” is the file “show
ing, for example, where [an employee] was born, the
names of his parents, where he has lived from time to
time, his . . . school records, results of examinations, [and]
evaluations of his work performance.” 425 U. S., at 377.
It is the file typically maintained in the human resources
office—otherwise known (to recall an example offered
above) as the “personnel department.” Ibid.
   Exemption 2 uses “personnel” in the exact same way.
An agency’s “personnel rules and practices” are its rules
and practices dealing with employee relations or human
resources. The D. C. Circuit, in a pre-Crooker decision,
gave as examples “matters relating to pay, pensions,
vacations, hours of work, lunch hours, parking, etc.”
Jordan, 591 F. 2d, at 763; see supra, at 3. That “etc.” is
important; we doubt any court could know enough about
the Federal Government’s operations to formulate a com
prehensive list. But all the rules and practices referenced
in Exemption 2 share a critical feature: They concern the
conditions of employment in federal agencies—such mat
ters as hiring and firing, work rules and discipline, com
pensation and benefits.4 Courts in practice have had little
——————
  4 Government records also must satisfy the other requirements of

Exemption 2 to be exempt from disclosure. Information must “relat[e]
solely”—meaning, as usual, “exclusively or only,” Random House 1354
8               MILNER v. DEPARTMENT OF NAVY

                          Opinion of the Court

difficulty identifying the records that qualify for withhold
ing under this reading: They are what now commonly fall
within the Low 2 exemption. Our construction of the
statutory language simply makes clear that Low 2 is all of
2 (and that High 2 is not 2 at all, see infra, at 10–14).
   The statute’s purpose reinforces this understanding of
the exemption. We have often noted “the Act’s goal of
broad disclosure” and insisted that the exemptions be
“given a narrow compass.” Department of Justice v. Tax
Analysts, 492 U. S. 136, 151 (1989); see Department of
Interior v. Klamath Water Users Protective Assn., 532 U. S.
1, 7–8 (2001).5 This practice of “constru[ing] FOIA exemp
tions narrowly,” Department of Justice v. Landano, 508
U. S. 165, 181 (1993), stands on especially firm footing
with respect to Exemption 2. As described earlier, Con
gress worded that provision to hem in the prior APA ex
emption for “any matter relating solely to the internal
management of an agency,” which agencies had used to
prevent access to masses of documents. See Rose, 425
U. S., at 362. We would ill-serve Congress’s purpose by
——————
—to the agency’s “personnel rules and practices.” And the information
must be “internal”; that is, the agency must typically keep the records
to itself for its own use. See Webster’s 1180 (“internal” means “existing
or situated within the limits . . . of something”). An agency’s human
resources documents will often meet these conditions.
   5 The dissent would reject this longstanding rule of construction in

favor of an approach asking courts “to turn Congress’ public informa
tion objectives into workable agency practice.” Post, at 8–9 (opinion of
BREYER, J.). But nothing in FOIA either explicitly or implicitly grants
courts discretion to expand (or contract) an exemption on this basis. In
enacting FOIA, Congress struck the balance it thought right—generally
favoring disclosure, subject only to a handful of specified exemptions—
and did so across the length and breadth of the Federal Government.
See, e.g., John Doe Agency v. John Doe Corp., 493 U. S. 146, 152–153
(1989). The judicial role is to enforce that congressionally determined
balance rather than, as the dissent suggests, post, at 4–6, to assess case
by case, department by department, and task by task whether disclo
sure interferes with good government.
                 Cite as: 562 U. S. ____ (2011)           9

                     Opinion of the Court

construing Exemption 2 to reauthorize the expansive
withholding that Congress wanted to halt. Our reading
instead gives the exemption the “narrower reach” Con
gress intended, id., at 363, through the simple device of
confining the provision’s meaning to its words.
   The Government resists giving “personnel” its plain
meaning on the ground that Congress, when drafting
Exemption 2, considered but chose not to enact language
exempting “internal employment rules and practices.”
Brief for Respondent 30–34, and n. 11. This drafting
history, the Navy maintains, proves that Congress did not
wish “to limit the Exemption to employment-related mat
ters,” id., at 31, even if the adjective “personnel” conveys
that meaning in other contexts, id., at 41. But we think
the Navy’s evidence insufficient: The scant history con
cerning this word change as easily supports the inference
that Congress merely swapped one synonym for another.
Cf. Mead Corp. v. Tilley, 490 U. S. 714, 723 (1989) (noting
with respect to the “unexplained disappearance of one
word from an unenacted bill” that “mute intermediate
legislative maneuvers are not reliable” aids to statutory
interpretation (internal quotation marks omitted)). Those
of us who make use of legislative history believe that clear
evidence of congressional intent may illuminate ambigu
ous text. We will not take the opposite tack of allowing
ambiguous legislative history to muddy clear statutory
language.
   Exemption 2, as we have construed it, does not reach
the ESQD information at issue here. These data and
maps calculate and visually portray the magnitude of
hypothetical detonations. By no stretch of imagination do
they relate to “personnel rules and practices,” as that term
is most naturally understood. They concern the physical
rules governing explosives, not the workplace rules gov
erning sailors; they address the handling of dangerous
10            MILNER v. DEPARTMENT OF NAVY

                      Opinion of the Court

materials, not the treatment of employees. The Navy
therefore may not use Exemption 2, interpreted in accord
with its plain meaning to cover human resources matters,
to prevent disclosure of the requested maps and data.
                           IV
   The Government offers two alternative readings of
Exemption 2 to support withholding the ESQD informa
tion. We cannot square either with the statute.
                              A
   The Navy first encourages us to adopt the construction
of Exemption 2 pioneered by Crooker, which shields mate
rial not only if it meets the criteria set out above (Low 2),
but also if it is “predominant[ly] interna[l]” and its “disclo
sure would significantly risk[] circumvention of federal
agency functions” (High 2). Brief for Respondent 41 (in
ternal quotation marks omitted). The dissent, too, favors
this reading of the statute. Post, at 1. But the Crooker
interpretation, as already suggested, suffers from a patent
flaw: It is disconnected from Exemption 2’s text. The High
2 test (in addition to substituting the word “predomi
nantly” for “solely,” see n. 1, supra) ignores the plain
meaning of the adjective “personnel,” see supra, at 6–9,
and adopts a circumvention requirement with no basis or
referent in Exemption 2’s language. Indeed, the only way
to arrive at High 2 is by taking a red pen to the statute—
“cutting out some” words and “pasting in others” until
little of the actual provision remains. Elliott v. Depart
ment of Agriculture, 596 F. 3d 842, 845 (CADC 2010).
Because this is so, High 2 is better labeled “Non 2” (and
Low 2 . . . just 2).
   In support of its text-light approach to the statute, the
Government relies primarily on legislative history, placing
particular emphasis on the House Report concerning
FOIA. See Brief for Respondent 33–38. A statement in
that Report buttresses the High 2 understanding of the
                      Cite as: 562 U. S. ____ (2011)                    11

                          Opinion of the Court

exemption and, indeed, specifically rejects the Low 2
construction. According to the Report: “Operating rules,
guidelines, and manuals of procedure for Government
investigators or examiners would be exempt from disclo
sure [under Exemption 2], but this exemption would not
cover . . . employee relations and working conditions and
routine administrative procedures.” H. R. Rep. No. 1497,
89th Cong., 2d Sess., 10 (1966). But the Senate Report
says exactly the opposite, explaining in support of a Low 2
interpretation that the phrase “internal personnel rules
and practices of an agency” means “rules as to personnel’s
use of parking facilities or regulation of lunch hours,
statements of policy as to sick leave, and the like.”
S. Rep., at 8.6 In Rose, we gave reasons for thinking the
Senate Report the more reliable of the two. See 425 U. S.,
at 366. But the more fundamental point is what we said
before: Legislative history, for those who take it into ac
count, is meant to clear up ambiguity, not create it. See
supra, at 9; Wong Yang Sung v. McGrath, 339 U. S. 33, 49
(1950) (declining to consult legislative history when that
“history is more conflicting than the text is ambiguous”).
When presented, on the one hand, with clear statutory
language and, on the other, with dueling committee re
ports, we must choose the language.
  The Government also advances, in support of Crooker’s
High 2 approach, an argument based on subsequent legis
lative action. Congress, the Government notes, amended
Exemption 7(E) in 1986 to cover law enforcement records
whose production “would disclose techniques and proce
dures for law enforcement investigations or prosecutions,

——————
  6 We are perplexed that the dissent takes seriously Crooker’s notion

that the reports are “reconcilable.” Post, at 4. To strip the matter to its
essentials, the House Report says: “Exemption 2 means A, but not B.”
The Senate Report says: “Exemption 2 means B.” That is the very
definition of “irreconcilable.”
12           MILNER v. DEPARTMENT OF NAVY

                     Opinion of the Court

or would disclose guidelines for law enforcement investi
gations or prosecutions if such disclosure could reason
ably be expected to risk circumvention of the law.”
§552(b)(7)(E). That amendment, the Government con
tends, codified Crooker’s “circumvention of the law” stan
dard and, in so doing, ratified Crooker’s holding. Brief for
Respondent 42–43. The dissent likewise counts as signifi
cant that Congress “t[ook] note” of Crooker in revising
FOIA. Post, at 9; see post, at 2.
   But the Government and the dissent neglect the key
feature of the 1986 amendment: Congress modified not
Exemption 2 (the subject of Crooker), but instead Exemp
tion 7(E). And the Crooker construction of Exemption 2
renders Exemption 7(E) superfluous and so deprives that
amendment of any effect. See, e.g., TRW Inc. v. Andrews,
534 U. S. 19, 31 (2001) (noting canon that statutes should
be read to avoid making any provision “superfluous, void,
or insignificant” (internal quotation marks omitted)). We
cannot think of any document eligible for withholding
under Exemption 7(E) that the High 2 reading does not
capture: The circumvention standard is the same, and the
law enforcement records listed in Exemption 7(E) are
“predominantly internal.” So if Congress had agreed with
Crooker’s reading of Exemption 2, it would have had no
reason to alter Exemption 7(E). In that event, Congress
would either have left the statute alone (on the theory that
Crooker would do the necessary work) or would have
amended Exemption 2 specifically to ratify Crooker. The
decision instead to amend Exemption 7(E) suggests that
Congress approved the circumvention standard only as to
law enforcement materials, and not as to the wider set of
records High 2 covers. Perhaps this legislative action does
not show that Congress affirmatively disagreed with
Crooker; maybe Congress was agnostic about whether the
circumvention standard should apply to other records.
But one thing is clear: The 1986 amendment does not
                     Cite as: 562 U. S. ____ (2011)                    13

                          Opinion of the Court

ratify, approve, or otherwise signal agreement with
Crooker’s interpretation of Exemption 2. This argument
therefore cannot save the High 2 construction.
  The dissent offers one last reason to embrace High 2,
and indeed stakes most of its wager on this argument.
Crooker, the dissent asserts, “has been consistently relied
upon and followed for 30 years” by other lower courts.
Post, at 9; see post, at 1–2. But this claim, too, trips at the
starting gate. It would be immaterial even if true, because
we have no warrant to ignore clear statutory language on
the ground that other courts have done so. And in any
event, it is not true. Prior to Crooker, three Circuits
adopted the reading of Exemption 2 we think right, and
they have not changed their minds. See n. 2, supra.7
——————
  7 The  dissent’s view that “two of th[ese] Circuits [have] not adher[ed]
to their early positions” is incorrect. Post, at 2. In Abraham & Rose,
P.L.C. v. United States, cited by the dissent, the Sixth Circuit rejected
the Government’s claim that Exemption 2 shielded records of federal
tax lien filings. 138 F. 3d 1075, 1082 (1998). The court nowhere
discussed the High 2 versus Low 2 question at issue here. Its only
reference to Crooker concerned the part of that decision interpreting
“solely” to mean “predominantly.” See 138 F.3d, at 1080; see also n. 1,
supra. Subsequently, the Sixth Circuit once again held, in Rugiero v.
Department of Justice, that Exemption 2 applies to “routine matters of
merely internal significance.” 257 F. 3d 534, 549 (2001). In Sladek v.
Bensinger, which the dissent also cites, the Fifth Circuit insisted that
the Government disclose a Drug Enforcement Administration agent’s
manual because it “is not the type of trivial rule, such as allocation of
parking facilities, that is covered by Exemption 2.” 605 F. 2d 899, 902
(1979). In confirming this Low 2 interpretation of the statute, the court
acknowledged that another Circuit had embraced the High 2 standard.
The court, however, declined to consider this alternative interpretation
because it would not have changed the case’s outcome. See ibid.
Finally, the Eighth Circuit’s last word on Exemption 2 is clear, and the
dissent does not say otherwise. The exemption, according to that most
recent Eighth Circuit decision, applies “only [to an agency’s] housekeep
ing matters.” Cox, 576 F. 2d, at 1309–1310 (internal quotation marks
omitted). The dissent is surely right to say, post at 2, that Crooker “has
guided nearly every FOIA case decided over the last 30 years” in
14              MILNER v. DEPARTMENT OF NAVY

                          Opinion of the Court

Since Crooker, three other Circuits have accepted the High
2 reading. See supra, at 3. One Circuit has reserved
judgment on the High 2-Low 2 debate. See Audubon
Society v. Forest Serv., 104 F. 3d 1201, 1203–1204 (CA10
1997). And the rest have not considered the matter. (No
one should think Crooker has been extensively discussed
or debated in the Courts of Appeals. In the past three
decades, Crooker’s analysis of Exemption 2 has been cited
a sum total of five times in federal appellate decisions
outside the D. C. Circuit—on average, once every six
years.) The result is a 4 to 3 split among the Circuits.8
We will not flout all usual rules of statutory interpretation
to take the side of the bare majority.
                              B
   Presumably because Crooker so departs from Exemption
2’s language, the Government also offers another con
struction, which it says we might adopt “on a clean slate,”
“based on the plain text . . . alone.” Brief for Respondent
15. On this reading, the exemption “encompasses records
concerning an agency’s internal rules and practices for its
personnel to follow in the discharge of their governmental
functions.” Id., at 20; see also id., at 13–14 (Exemption 2
“applies generally to matters concerning internal rules
and practices to guide agency personnel in performing
——————
Circuits applying Crooker; but that statement does not hold in the
Circuits using the Low 2 approach.
   8 Notably, even those courts approving Crooker have disagreed about

how to apply High 2. Fault lines include whether the risk of circum
vention must be significant, see, e.g., Hidalgo v. FBI, 541 F. Supp. 2d
250, 253 (DC 2008); Pet. for Cert. 15–16; whether courts should con
sider the public interest in disclosure when calculating that risk, see,
e.g., Department of Justice, Guide to the Freedom of Information Act,
p. 185 (2009); and whether an agency must regulate the person or
entity threatening circumvention; compare, e.g., 575 F. 3d, at 971, with,
e.g., id., at 978 (W. Fletcher, J., dissenting). The disagreement is not
surprising. Because High 2 is nowhere evident in the statute, courts
lack the normal guideposts for ascertaining its coverage.
                 Cite as: 562 U. S. ____ (2011)          15

                     Opinion of the Court

their duties”). According to the Government, this inter
pretation makes sense because “the phrase ‘personnel
rules and practices of an agency’ is logically understood to
mean an agency’s rules and practices for its personnel.”
Id., at 20 (emphasis added).
   But the purported logic in the Government’s definition
eludes us. We would not say, in ordinary parlance, that a
“personnel file” is any file an employee uses, or that a
“personnel department” is any department in which an
employee serves. No more would we say that a “personnel
rule or practice” is any rule or practice that assists an
employee in doing her job. The use of the term “personnel”
in each of these phrases connotes not that the file or de
partment or practice/rule is for personnel, but rather that
the file or department or practice/rule is about personnel—
i.e., that it relates to employee relations or human re
sources. This case well illustrates the point. The records
requested, as earlier noted, are explosives data and maps
showing the distances that potential blasts travel. This
information no doubt assists Navy personnel in storing
munitions. But that is not to say that the data and maps
relate to “personnel rules and practices.” No one staring
at these charts of explosions and using ordinary language
would describe them in this manner.
   Indeed, the Government’s “clean slate” construction
reaches such documents only by stripping the word “per
sonnel” of any real meaning. Under this interpretation,
an agency’s “internal personnel rules and practices” ap
pears to mean all its internal rules and practices. That is
because agencies necessarily operate through personnel,
and so all their internal rules and practices are for per
sonnel. The modifier “personnel,” then, does no modifying
work; it does not limit the class of internal rules and
practices that Exemption 2 covers. What is most naturally
viewed as the provision’s key word—the term that ought
16              MILNER v. DEPARTMENT OF NAVY

                         Opinion of the Court

to define its scope—does nothing more than state the
truism that in an agency it is “personnel” who follow
internal rules and practices.
   And this odd reading would produce a sweeping exemp
tion, posing the risk that FOIA would become less a dis
closure than “a withholding statute.” Mink, 410 U. S., at
79. Many documents an agency generates in some way
aid employees in carrying out their responsibilities. If
Exemption 2 were to reach all these records, it would tend
to engulf other FOIA exemptions, rendering ineffective the
limitations Congress placed on their application. Exemp
tion 7, for example, shields records compiled for law en
forcement purposes, but only if one of six specified criteria
is met. §552(b)(7). Yet on the Government’s view, an
agency could bypass these restrictions by invoking Exemp
tion 2 whenever law enforcement records guide personnel
in performing their duties. Indeed, an agency could use
Exemption 2 as an all-purpose back-up provision to with
hold sensitive records that do not fall within any of FOIA’s
more targeted exemptions.9
——————
  9 The dissent asserts that “30 years of experience” with a more expan
sive interpretation of the exemption suggests no “seriou[s] inter
fere[nce] with . . . FOIA’s informational objectives.” Post, at 6. But
those objectives suffer any time an agency denies a FOIA request based
on an improper interpretation of the statute. To give just one example,
the U. S. Forest Service has wrongly invoked Exemption 2 on multiple
occasions to withhold information about (of all things) bird nesting
sites. See Audubon Society v. Forest Serv., 104 F. 3d 1201, 1203 (CA10
1997); Maricopa Audubon Soc. v. Forest Serv., 108 F. 3d 1082, 1084
(CA9 1997). And recent statistics raise a concern that federal agencies
may too readily use Exemption 2 to refuse disclosure. According to
amicus Public Citizen, “while reliance on exemptions overall rose 83%
from 1998 to 2006, reliance on Exemption 2 rose 344% during that
same time period.” Brief for Public Citizen et al. as Amici Curiae 24.
In 2009 alone, federal departments cited Exemption 2 more than 72,000
times to prevent access to records. See Brief for Allied Daily Newspa
pers of Washington et al. as Amici Curiae 3. We do not doubt that
many of these FOIA denials were appropriate. But we are unable to
                    Cite as: 562 U. S. ____ (2011)                17

                        Opinion of the Court

  Interpreted in this way, Exemption 2—call it “Super 2”
now—would extend, rather than narrow, the APA’s former
exemption for records relating to the “internal manage
ment of an agency.” 5 U. S. C. §1002 (1964 ed.). We doubt
that even the “internal management” provision, which
Congress thought allowed too much withholding, see
supra, at 2, would have protected all information that
guides employees in the discharge of their duties, includ
ing the explosives data and maps in this case. And per
haps needless to say, this reading of Exemption 2 violates
the rule favoring narrow construction of FOIA exemptions.
See, e.g., Abramson, 456 U. S., at 630; Rose, 425 U. S., at
361. Super 2 in fact has no basis in the text, context, or
purpose of FOIA, and we accordingly reject it.
                              V
   Although we cannot interpret Exemption 2 as the Gov
ernment proposes, we recognize the strength of the Navy’s
interest in protecting the ESQD data and maps and other
similar information. The Government has informed us
that “[p]ublicly disclosing the [ESQD] information would
significantly risk undermining the Navy’s ability to safely
and securely store military ordnance,” Brief for Respon
dent 47, and we have no reason to doubt that representa
tion. The Ninth Circuit similarly cautioned that disclo
sure of this information could be used to “wrea[k] havoc”
and “make catastrophe more likely.” 575 F. 3d, at 971.
Concerns of this kind—a sense that certain sensitive
information should be exempt from disclosure—in part led
the Crooker court to formulate the High 2 standard. See
670 F. 2d, at 1074 (contending that “common sense” sup
ported the High 2 interpretation because Congress would
not have wanted FOIA to “undermin[e] . . . the effective
——————
accept the dissent’s unsupported declaration that a sweeping construc
tion of Exemption 2 has not interfered with Congress’s goal of broad
disclosure.
18            MILNER v. DEPARTMENT OF NAVY

                      Opinion of the Court

ness of law enforcement agencies”). And we acknowledge
that our decision today upsets three decades of agency
practice relying on Crooker, and therefore may force con
siderable adjustments.
   We also note, however, that the Government has other
tools at hand to shield national security information and
other sensitive materials. Most notably, Exemption 1 of
FOIA prevents access to classified documents. §552(b)(1);
see 575 F. 3d, at 980 (W. Fletcher, J., dissenting) (Exemp
tion 1 is “specifically designed to allow government agen
cies to withhold information that might jeopardize our
national security”). The Government generally may clas
sify material even after receiving a FOIA request, see
Exec. Order No. 13526, §1.7(d), 75 Fed. Reg. 711 (2009);
an agency therefore may wait until that time to decide
whether the dangers of disclosure outweigh the costs of
classification. See Tr. of Oral Arg. 29–30. Exemption 3
also may mitigate the Government’s security concerns.
That provision applies to records that any other statute
exempts from disclosure, §552(b)(3), thus offering Con
gress an established, streamlined method to authorize the
withholding of specific records that FOIA would not oth
erwise protect. And Exemption 7, as already noted, pro
tects “information compiled for law enforcement purposes”
that meets one of six criteria, including if its release “could
reasonably be expected to endanger the life or physical
safety of any individual.” §552(b)(7)(F). The Navy argued
below that the ESQD data and maps fall within Exemp
tion 7(F), see n. 3, supra, and that claim remains open for
the Ninth Circuit to address on remand.
   If these or other exemptions do not cover records whose
release would threaten the Nation’s vital interests, the
Government may of course seek relief from Congress. See
Tr. of Oral Arg. 48. All we hold today is that Congress has
not enacted the FOIA exemption the Government desires.
                  Cite as: 562 U. S. ____ (2011)           19

                      Opinion of the Court

We leave to Congress, as is appropriate, the question
whether it should do so.
                              VI
  Exemption 2, consistent with the plain meaning of the
term “personnel rules and practices,” encompasses only
records relating to issues of employee relations and human
resources. The explosives maps and data requested here
do not qualify for withholding under that exemption. We
therefore reverse the judgment of the Court of Appeals
and remand the case for further proceedings consistent
with this opinion.
                                             It is so ordered.
                 Cite as: 562 U. S. ____ (2011)            1

                     ALITO, J., concurring

SUPREME COURT OF THE UNITED STATES
                         _________________

                         No. 09–1163
                         _________________


GLEN SCOTT MILNER, PETITIONER v. DEPARTMENT
               OF THE NAVY
 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF

            APPEALS FOR THE NINTH CIRCUIT

                        [March 7, 2011] 


   JUSTICE ALITO, concurring.
   I agree with the Court that the text of Exemption 2 of
the Freedom of Information Act of 1966 cannot support
the “High 2” interpretation that courts have adopted and
applied over the years. As the Court explains, however,
the Government may avail itself of numerous other ex
emptions, see ante, at 18—exemptions that may have been
overshadowed in recent years by the broad reach of High
2. I write separately to underscore the alternative argu
ment that the Navy raised below, which rested on Exemp
tion 7(F) and which will remain open on remand. See
ante, at 5, n. 3, 18.
   Exemption 7 applies to specific categories of information
“compiled for law enforcement purposes.” 5 U. S. C.
§552(b)(7). In particular, Exemption 7(F) permits with
holding of “records or information compiled for law en
forcement purposes” that, if disclosed, “could reasonably
be expected to endanger the life or physical safety of any
individual.” §552(b)(7)(F). In most cases involving secu
rity information, it is not difficult to show that disclosure
may “endanger the life or physical safety of any individ
ual.” A more difficult question, however, is whether the
information is “compiled for law enforcement purposes.”
See John Doe Agency v. John Doe Corp., 493 U. S. 146, 153
(1989) (“Before it may invoke [Exemption 7], the Govern
2             MILNER v. DEPARTMENT OF NAVY

                      ALITO, J., concurring

ment has the burden of proving the existence of . . . a
compilation for such a purpose”). In my view, this phrase
reasonably encompasses information used to fulfill official
security and crime prevention duties.
   “Law enforcement purposes.” The ordinary understand
ing of law enforcement includes not just the investigation
and prosecution of offenses that have already been com
mitted, but also proactive steps designed to prevent crimi
nal activity and to maintain security. A “law enforcement
officer” is defined as one “whose duty it is to preserve the
peace,” Black’s Law Dictionary 796 (5th ed. 1979), and
fulfilling that duty involves a range of activities. Police on
the beat aim to prevent crime from occurring, and they no
less carry out “law enforcement purposes” than officers
investigating a crime scene. Similarly, a “law-enforcement
agency” is charged with “the apprehension of alleged
offenders as well as crime detection and prevention.” R. De
Sola, Crime Dictionary 82 (1982) (emphasis added).
   Crime prevention and security measures are critical to
effective law enforcement as we know it. There can be no
doubt, for example, that the Secret Service acts with a
law enforcement purpose when it protects federal officials
from attack, even though no investigation may be ongoing.
Likewise, steps by law enforcement officers to prevent
terrorism surely fulfill “law enforcement purposes.” Par
ticularly in recent years, terrorism prevention and na
tional security measures have been recognized as vital to
effective law enforcement efforts in our Nation. Indeed,
“[a]fter the September 11th attacks on America,” the
priorities of the Federal Bureau of Investigation “shifted
dramatically,” and the FBI’s “top priority became the
prevention of another terrorist attack.” Hearings before
the Subcommittee on Science, the Departments of State,
Justice, and Commerce, and Related Agencies of the
House Committee on Appropriations, 109th Cong., 2d
Sess., pt. 10, 232 (2006) (testimony of FBI Director Robert
                 Cite as: 562 U. S. ____ (2011)           3

                     ALITO, J., concurring

S. Mueller III). Today, “[t]he FBI’s number one priority
continues to be the prevention of terrorist attacks against
the United States.” Hearings before the Senate Commit
tee on Homeland Security and Governmental Affairs,
111th Cong., 2d Sess, p. ___ (Sept. 22, 2010) (testimony of
Mueller). If crime prevention and security measures do
not serve “law enforcement purposes,” then those charged
with law enforcement responsibilities have little chance of
fulfilling their duty to preserve the peace.
  The context of Exemption 7 confirms that, read natu
rally, “law enforcement purposes” involve more than just
investigation and prosecution. As Exemption 7’s subpara
graphs demonstrate, Congress knew how to refer to these
narrower activities. See, e.g., §552(b)(7)(A) (information
that “could reasonably be expected to interfere with en
forcement proceedings”); §552(b)(7)(E) (information that
“would disclose techniques and procedures for law en
forcement investigations or prosecutions”).       Congress’
decision to use different language to trigger Exemption 7
confirms that the concept of “law enforcement purposes”
sweeps in activities beyond investigation and prosecution.
See Sosa v. Alvarez-Machain, 542 U. S. 692, 711, n. 9
(2004) (applying the “usual rule” that “ when the legis
lature uses certain language in one part of the statute
and different language in another, the court assumes dif-
ferent meanings were intended” (internal quotation marks
omitted)).
  “Compiled for law enforcement purposes.” This Court
has given a fairly broad meaning to “compiled” under
§552(b)(7). In John Doe Agency, we held that information
need not have been originally “compiled for law enforce
ment purposes” to satisfy Exemption 7’s threshold re
quirement. Rather, “even though . . . documents were put
together at an earlier time for a different purpose,” they
may fall within Exemption 7 if they are later assembled
for law enforcement purposes. 493 U. S., at 154–155. For
4            MILNER v. DEPARTMENT OF NAVY

                     ALITO, J., concurring

example, documents originally gathered for routine busi
ness purposes may fall within Exemption 7 if they are
later compiled for use in a criminal investigation. Simi
larly, federal building plans and related information—
which may have been compiled originally for architectural
planning or internal purposes—may fall within Exemption
7 if that information is later compiled and given to law
enforcement officers for security purposes.
  Documents compiled for multiple purposes are not nec-
essarily deprived of Exemption 7’s protection. The text
of Exemption 7 does not require that the information
be compiled solely for law enforcement purposes. Cf.
§552(b)(2) (“related solely to the internal personnel rules
and practices of an agency”). Therefore, it may be
enough that law enforcement purposes are a significant
reason for the compilation.
  In this case, the Navy has a fair argument that the
Explosive Safety Quantity Distance (ESQD) information
falls within Exemption 7(F). The ESQD information, the
Navy argues, is used “for the purpose of identifying and
addressing security issues” and for the “protection of
people and property on the base, as well as in [the] nearby
community, from the damage, loss, death, or injury that
could occur from an accident or breach of security.” Brief
for Appellee in No. 07–36056 (CA9), pp. 39–40. If, indeed,
the ESQD information was compiled as part of an effort to
prevent crimes of terrorism and to maintain security,
there is a reasonable argument that the information has
been “compiled for law enforcement purposes.” §552(b)(7).
Assuming that this threshold requirement is satisfied, the
ESQD information may fall comfortably within Exemption
7(F).
                 Cite as: 562 U. S. ____ (2011)            1

                     BREYER, J., dissenting

SUPREME COURT OF THE UNITED STATES
                         _________________

                         No. 09–1163
                         _________________


GLEN SCOTT MILNER, PETITIONER v. DEPARTMENT
               OF THE NAVY
 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF

            APPEALS FOR THE NINTH CIRCUIT

                        [March 7, 2011] 


   JUSTICE BREYER, dissenting.
   Justice Stevens has explained that, once “a statute has
been construed, either by this Court or by a consistent
course of decision by other federal judges and agencies,” it
can acquire a clear meaning that this Court should hesi
tate to change. See Shearson/American Express Inc. v.
McMahon, 482 U. S. 220, 268 (1987) (opinion concurring in
part and dissenting in part) (emphasis added). See also
Commissioner v. Fink, 483 U. S. 89, 104 (1987) (Stevens,
J., dissenting); B. Cardozo, The Nature of the Judicial
Process 149 (1921). I would apply that principle to this
case and accept the 30-year-old decision by the D. C. Cir
cuit in Crooker v. Bureau of Alcohol, Tobacco & Firearms,
670 F. 2d 1051 (1981) (en banc), as properly stating the
law.
   For one thing, the Crooker decision, joined by 9 of the 10
sitting Circuit Judges, has been consistently followed, or
favorably cited, by every Court of Appeals to have consid
ered the matter during the past 30 years. See ibid. (writ
ten by Judge Edwards, and joined by Chief Judge Robin
son and Judges Wright, MacKinnon, Robb, Wald, Mikva,
and then-Judge Ginsburg, with Judge Tamm concurring
in the result and Judge Wilkey dissenting); Massey v. FBI,
3 F. 3d 620, 622 (CA2 1993); Kaganove v. EPA, 856 F. 2d
884, 889 (CA7 1988), cert. denied, 488 U. S. 1011 (1989);
2            MILNER v. DEPARTMENT OF NAVY

                    BREYER, J., dissenting

Dirksen v. HHS, 803 F. 2d 1456, 1458 (CA9 1986). Three
Circuits adopted a different approach in the 1970’s before
Crooker was decided, see ante, at 3–4, n. 2, but I read
subsequent decisions in two of those Circuits as not adher
ing to their early positions. See Abraham & Rose, PLC v.
United States, 138 F. 3d 1075, 1080–1081 (CA6 1998)
(finding Crooker’s textual analysis “sound and persuasive,”
and noting that FBI symbols “used internally to identify
confidential sources” may be withheld); Sladek v.
Bensinger, 605 F. 2d 899, 902 (CA5 1979) (expressly re
serving judgment on the Crooker issue). As for the re
maining Circuit, its district courts understand Crooker
now to apply. See, e.g., Gavin v. SEC, No. 04–4522, 2007
WL 2454156, *5–*6 (D Minn., Aug. 23, 2007); see also
McQueen v. United States, 264 F. Supp. 2d 502, 528 (SD
Tex. 2003), aff’d, 100 Fed. Appx. 964 (CA5 2004) (per
curiam); Tickel v. IRS, No. 1–85–709, 1986 WL 14436, *2–
*3 (ED Tenn., Aug. 22, 1986). I recognize that there is
reasonable ground for disagreement over the precise
status of certain pre-Crooker precedents, but the Crooker
interpretation of Exemption 2 has guided nearly every
Freedom of Information Act (FOIA) case decided over the
last 30 years. See generally Dept. of Justice, Guide to
Freedom of Information Act, pp. 184–206 (2009) (FOIA
Guide) (identifying over 100 district court decisions apply
ing the Crooker approach, and one appearing to reject it).
   Congress, moreover, well aware of Crooker, left Exemp
tion 2, 5 U. S. C. §552(b)(2), untouched when it amended
the FOIA five years later. See S. Rep. No. 98–221, p. 25
(1983) (discussing Crooker); Freedom of Information Re
form Act of 1986, 100 Stat. 3207–48 (amending Exemption
7, 5 U. S. C. §552(b)(7)).
   This Court has found that circumstances of this kind
offer significant support for retaining an interpretation of
a statute that has been settled by the lower courts. See
General Dynamics Land Systems, Inc. v. Cline, 540 U. S.
                 Cite as: 562 U. S. ____ (2011)            3

                     BREYER, J., dissenting

581, 593–594 (2004); Evans v. United States, 504 U. S.
255, 268–269 (1992); Newman-Green, Inc. v. Alfonzo-
Larrain, 490 U. S. 826, 833 (1989); Monessen Southwest
ern R. Co. v. Morgan, 486 U. S. 330, 338–339 (1988); Lin
dahl v. Office of Personnel Management, 470 U. S. 768,
781–783 (1985); Herman & MacLean v. Huddleston, 459
U. S. 375, 385–386 (1983); Cannon v. University of Chi
cago, 441 U. S. 677, 702–703 (1979); Blue Chip Stamps
v. Manor Drug Stores, 421 U. S. 723, 731–732 (1975);
Gulf Oil Corp. v. Copp Paving Co., 419 U. S. 186, 200–
201 (1974); Blau v. Lehman, 368 U. S. 403, 412–413
(1962). See generally W. Eskridge, P. Frickey, & E. Garrett,
Cases and Materials on Legislation 1048 (4th ed. 2007)
(“[T]he acquiescence rule can also support implicit con
gressional ratification of a uniform line of federal appel
late interpretations . . .”).
    For another thing, even if the majority’s analysis would
have persuaded me if written on a blank slate, Crooker’s
analysis was careful and its holding reasonable. The
Circuit Court examined the statute’s language, the legisla
tive history, and the precedent. It recognized that the
exemption’s words (“related solely to the internal person
nel rules and practices of an agency”) could easily be read,
as the Court reads them today, to refer only to human
resources rules and practices. See 670 F. 2d, at 1056–
1057. But it also thought that those words could be read
more broadly as referring to internal rules or practices
that set forth criteria or guidelines for agency personnel to
follow in respect to purely internal matters (as long as the
information at issue was “not of legitimate public inter
est”). Id., at 1056, 1057.
    The D. C. Circuit agreed with today’s Court that the
Senate Report described the exemption as referring to
“ ‘internal personnel’ ” matters, giving as examples “ ‘per
sonnel’s use of parking facilities, . . . sick leave, and the
like.’ ” Id., at 1058–1059 (quoting S. Rep. No. 813, 89th
4            MILNER v. DEPARTMENT OF NAVY

                    BREYER, J., dissenting

Cong., 1st Sess., p. 8 (1965)). But it also noted that the
House Report described the exemption as protecting from
disclosure “ ‘[o]perating rules, guidelines, and manuals of
procedure for Government investigators or examiners.’ ”
670 F. 2d, at 1060 (quoting H. R. Rep. No. 1497, 89th
Cong., 2d Sess., p. 10 (1966)). “[U]pon reflection,” it
thought the views of the two Houses “reconcilable” if one
understood both sets of examples as referring to internal
staff information (both minor personnel matters and staff
instruction matters) that the public had no legitimate
interest in learning about. 670 F. 2d, at 1065. And it
accepted this view in light of its hesitation to “apply indi
vidual provisions of the statute woodenly, oblivious to
Congress’ intention that FOIA not frustrate law enforce
ment efforts.” Id., at 1066. At the same time it found no
other exemption that would protect internal documents in
which there is no legitimate public interest in disclosure—
a category that includes, say, building plans, safe combi
nations, computer passwords, evacuation plans, and the
like.
   After examining in depth the legislative history and
relevant precedent, the court adopted an approach based
on a prior opinion by Circuit Judge Leventhal, as well as
language used by this Court in Department of Air Force v.
Rose, 425 U. S. 352, 369 (1976). The D. C. Circuit held
that a document fits within the literal language of Exemp
tion 2 and is exempt from disclosure if (1) it “meets the
test of ‘predominant internality,’ ” i.e., the document is
“not of legitimate public interest,” and (2) “disclosure
significantly risks circumvention of agency regulations or
statutes.” Crooker, supra, at 1056, 1074; see also Rose,
supra, at 369 (suggesting that Exemption 2 might apply
where “disclosure may risk circumvention of agency regu
lation”). This test, based upon Congress’ broader FOIA
objectives and a “common sense” view of what information
Congress did and did not want to make available, Crooker,
                 Cite as: 562 U. S. ____ (2011)            5

                     BREYER, J., dissenting

supra, at 1074, takes the “practical approach” that this
Court has “consistently . . . taken” when interpreting the
FOIA, John Doe Agency v. John Doe Corp., 493 U. S. 146,
157 (1989).
   I would not underestimate the importance of this “prac
tical approach.” It reflects this Court’s longstanding rec
ognition that it cannot interpret the FOIA (and the Ad
ministrative Procedure Act (APA) of which it is a part)
with the linguistic literalism fit for interpretations of the
tax code. See generally 1 R. Pierce, Administrative Law
Treatise §7.1, p. 413 (4th ed. 2002) (“Judicial interpreta
tion of the malleable language of the APA has produced
changes in the rulemaking procedure that could be charac
terized as revolutionary if they had been affected in a day
or a year rather than gradually over a period of decades”);
cf. Sunstein & Vermeule, Interpretation and Institutions,
101 Mich. L. Rev. 885, 917–918, and n. 111 (2003) (observ
ing that Congress “appears to rely on courts for long peri
ods of time” to give meaning to the APA, which justifies
interpreting it less formalistically than statutes like “the
Internal Revenue Code”). That in large part is because
the FOIA (like the APA but unlike the tax code) must
govern the affairs of a vast Executive Branch with numer
ous different agencies, bureaus, and departments, per
forming numerous tasks of many different kinds. Too
narrow an interpretation, while working well in the case
of one agency, may seriously interfere with congressional
objectives when applied to another. The D. C. Circuit’s
answer to this legal problem here was to interpret Exemp
tion 2 in light of Congress’ basic effort to achieve a
“workable balance between the interests of the public in
greater access to information and the needs of the Gov
ernment to protect certain kinds of information from
disclosure.” John Doe Agency, supra, at 157. See also
S. Rep. No. 1219, 88th Cong., 2d Sess., 8, 11 (1964) (em
phasizing this “workable” balance); S. Rep. No. 813, at 3, 5
6            MILNER v. DEPARTMENT OF NAVY

                    BREYER, J., dissenting

(same); H. R. Rep. No. 1497, at 2, 6 (same).
   Further, 30 years of experience with Crooker’s holding
suggests that it has not seriously interfered with the
FOIA’s informational objectives, while at the same time it
has permitted agencies to withhold much information
which, in my view, Congress would not have wanted to
force into the public realm. To focus only on the case law,
courts have held that that information protected by Ex
emption 2 includes blueprints for Department of Agricul
ture buildings that store biological agents, Elliot v. De
partment of Agriculture, 518 F. Supp. 2d 217 (DC 2007);
documents that would help hackers access National Aero
nautics and Space Administration computers, Knight v.
NASA, No. 2:04–cv–2054–MCE–GGH, 2006 WL 3780901,
*6 (ED Cal., Dec. 21, 2006); agency credit card numbers,
Judicial Watch, Inc. v. Department of Commerce, 83
F. Supp. 2d 105, 110 (DC 1999); Commodity Futures
Trading Commission guidelines for settling cases, Shu
maker, Loop & Kendrick, LLP v. Commodity Futures
Trading Comm’n, No. 3:97 CV 7139, 1997 U. S. Dist.
LEXIS 23993, *10–*15 (ND Ohio, May 27, 1997); “trigger
figures” that alert the Department of Education to possible
mismanagement of federal funds, Wiesenfelder v. Riley,
959 F. Supp. 532, 536 (DC 1997); security plans for the
Supreme Court Building and Supreme Court Justices,
Voinche v. FBI, 940 F. Supp. 323, 328–329 (DC 1996);
vulnerability assessments of Commerce Department com
puter security plans, Schreibman v. Department of Com
merce, 785 F. Supp. 164, 165–166 (DC 1991); Bureau of
Prisons guidelines for controlling riots and for storing
hazardous chemicals, Miller v. DOJ, No. 87–0533, 1989
WL 10598 (DC, Jan. 31, 1989); guidelines for assessing the
sensitivity of military programs, Institute for Policy Stud
ies v. Department of Air Force, 676 F. Supp. 3, 4–5 (DC
1987); and guidelines for processing Medicare reimburse
ment claims, Dirksen, 803 F. 2d, at 1458–1459.
                  Cite as: 562 U. S. ____ (2011)            7

                     BREYER, J., dissenting

   In other Exemption 2 cases, where withholding may
seem less reasonable, the courts have ordered disclosure.
Cf. ante, at 16, n. 9 (citing Audubon Society v. Forest Serv.,
104 F. 3d 1201, 1203 (CA10 1997), and Maricopa Audubon
Soc. v. Forest Serv., 108 F. 3d 1082, 1084 (CA9 1997)). See
generally FOIA Guide 201, and n. 106 (citing nine deci
sions applying the Crooker approach but nonetheless
requiring disclosure).
   The majority acknowledges that “our decision today
upsets three decades of agency practice relying on Crooker,
and therefore may force considerable adjustments.” Ante,
at 18. But how are these adjustments to be made? Should
the Government rely upon other exemptions to provide the
protection it believes necessary? As JUSTICE ALITO notes,
Exemption 7 applies where the documents consist of “re
cords or information compiled for law enforcement pur
poses” and release would, e.g., “disclose techniques and
procedures for law enforcement investigations,” or “could
reasonably be expected to endanger the life or physical
safety of any individual.” 5 U. S. C. §552(b)(7). But what
about information that is not compiled for law enforce
ment purposes, such as building plans, computer pass
words, credit card numbers, or safe deposit combinations?
The Government, which has much experience litigating
FOIA cases, warns us that Exemption 7 “targets only a
subset of the important agency functions that may be
circumvented.” Brief for Respondent 52–53. Today’s
decision only confirms this point, as the Court’s insistence
on narrow construction might persuade judges to avoid
reading Exemption 7 broadly enough to provide Crooker
type protection.
   The majority suggests that the Government can classify
documents that should remain private. Ante, at 18. See 5
U. S. C. §552(b)(1) (permitting withholding of material
“properly classified” as authorized to be “kept secret in the
interest of national defense or foreign policy”). But classi
8             MILNER v. DEPARTMENT OF NAVY

                     BREYER, J., dissenting

fication is at best a partial solution. It takes time. It is
subject to its own rules. As the Government points out, it
would hinder the sharing of information about Govern
ment buildings with “first responders,” such as local fire
and police departments. Brief for Respondent 53–54. And
both Congress and the President believe the Nation cur
rently faces a problem of too much, not too little, classified
material. See Reducing Over-Classification Act, 124 Stat.
2648; Exec. Order No. 13526, §§1.3(d), 2.1(d), 5.4(d)(10), 3
CFR 298, 299–300, 304, 321 (2009 Comp.). Indeed, Con
gress recently found:
    “The 9/11 Commission and others have observed that
    the over-classification of information interferes with
    accurate, actionable, and timely information sharing,
    increases the cost of information security, and need
    lessly limits stakeholder and public access to informa
    tion.
       “Over-classification of information causes consider
    able confusion regarding what information may be
    shared with whom, and negatively affects the dis
    semination of information within the Federal Gov
    ernment and with State, local, and tribal entities, and
    with the private sector.” Reducing Over-Classification
    Act, §§2(2), (3), 124 Stat. 2648.
These legislative findings suggest that it is “over
classification,” not Crooker, that poses the more serious
threat to the FOIA’s public information objectives.
   That leaves congressional action. As the Court points
out, Congress remains free to correct whatever problems it
finds in today’s narrowing of Exemption 2. But legislative
action takes time; Congress has much to do; and other
matters, when compared with a FOIA revision, may war
rant higher legislative priority. In my view, it is for the
courts, through appropriate interpretation, to turn Con
gress’ public information objectives into workable agency
                Cite as: 562 U. S. ____ (2011)          9

                   BREYER, J., dissenting

practice, and to adhere to such interpretations once they
are settled.
  That is why: Where the courts have already interpreted
Exemption 2, where that interpretation has been consis
tently relied upon and followed for 30 years, where Con
gress has taken note of that interpretation in amending
other parts of the statute, where that interpretation is
reasonable, where it has proved practically helpful and
achieved commonsense results, where it is consistent with
the FOIA’s overall statutory goals, where a new and dif
ferent interpretation raises serious problems of its own,
and where that new interpretation would require Con
gress to act just to preserve a decades-long status quo,
I would let sleeping legal dogs lie.
  For these reasons, with respect, I dissent.
