concurring in the judgment.
I concur in the judgment. Given the prior access by accountants retained by the taxpayers to the papers involved in these cases and the wholly business rather than personal nature of the papers, I agree that the privilege against compelled self-incrimination did not in either of these cases protect the papers from production in response to the summonses. See Couch v. United States, 409 U. S. 322, 335-336 (1973); id., at 337 (Brennan, J., concurring). I do not join the Court’s opinion, however, because of the portent of much of what is said of a serious crippling of the protection secured by the privilege against compelled production of one’s private books and papers. Like today’s decision in United States v. Miller, post, p. 435, it is but another step in the denigration of privacy principles settled nearly 100 years ago in Boyd v. United States, 116 U. S. 616 *415(1886). According to the Court, “[w]hether the Fifth Amendment would shield the taxpayer from producing his own tax records in his possession is a question not involved here; for the papers demanded here are not his 'private papers.' ” Ante, at 414. This implication that the privilege might not protect against compelled production of tax records that are his “private papers” is so contrary to settled constitutional jurisprudence that this and other like implications throughout the opinion 1 prompt me to conjecture that once again the Court is laying the groundwork for future decisions that will tell us that the question here formally reserved was actually answered against the availability of the privilege. Semble, Hudgens v. NLRB, 424 U. S. 507 (1976). It is therefore appropriate to recall that history and this Court have construed the constitutional privilege to safeguard against governmental intrusions of personal privacy to compel either self-incriminating oral statements or the production of self-incriminating evidence recorded in one's private books and papers. Although as phrased in the Fifth Amendment — “nor shall [any person] be compelled in any criminal case to be a witness against himself” — the privilege makes no express reference, as does the Fourth Amendment, to “papers, and effects,” private papers have long been held to have the protection of the privilege, designed as it is “to maintain inviolate large areas of personal privacy.” Feldman v. United States, 322 U. S. 487, 490 (1944).
*416I
Expressions are legion in opinions of this Court that the protection of personal privacy is a central purpose of the privilege against compelled self-incrimination. “[I]t is the invasion of [a person’s] indefeasible right of personal security, personal liberty and private property” that “constitutes the essence of the offence” that violates the privilege. Boyd v. United States, supra, at 630. The privilege reflects “our respect for the inviolability of the human personality and of the right of each individual ‘to a private enclave where he may lead a private life.’ ” Murphy v. Waterfront Comm’n, 378 U. S. 52, 55 (1964). “It respects a private inner sanctum of individual feeling and thought and proscribes state intrusion to extract self-condemnation.” Couch v. United States, supra, at 327. See also Tehan v. United States ex rel. Shott, 382 U. S. 406, 416 (1966); Miranda v. Arizona, 384 U. S. 436, 460 (1966). “The Fifth Amendment in its Self-Incrimination Clause enables the citizen to create a zone of privacy which government may not force him to surrender to his detriment.” Griswold v. Connecticut, 381 U. S. 479, 484 (1965). See also Katz v. United States, 389 U. S. 347, 350 n. 5 (1967).
The Court pays lip service to this bedrock premise of privacy in the statement that “[wjithin the limits imposed by the language of the Fifth Amendment, which we necessarily observe, the privilege truly serves privacy interests,” ante, at 399. But this only makes explicit what elsewhere highlights the opinion, namely, the view that protection of personal privacy is merely a byproduct and not, as our precedents and history teach, a factor controlling in part the determination of the scope of the privilege. This cart-before-the-horse approach is fundamentally at odds with the settled principle that the scope of the privilege is not constrained by the limits of the *417wording of the Fifth Amendment but has the reach necessary to protect the cherished value of privacy which it safeguards. See Schmerber v. California, 384 U. S. 757, 761-762, n. 6 (1966). The “Court has always construed provisions of the Constitution having regard to the principles upon which it was established. The direct operation or literal meaning of the words used do not measure the purpose or scope of its provisions..." United States v. Lefkowitz, 285 U. S. 452, 467 (1932). “It has been repeatedly decided that [the Fifth Amendment] should receive a liberal construction, so as to prevent stealthy encroachment upon or ‘gradual depreciation' of the rights secured by [it], by imperceptible practice of courts or by well-intentioned but mistakenly over-zealous executive officers.” Gouled v. United States, 255 U. S. 298, 304 (1921). See Maness v. Meyers, 419 U. S. 449, 461 (1975). History and principle, not the mechanical application of its wording, have been the life of the Amendment.2
That the privilege does not protect against the production of private information where there is no compulsion, or where immunity is granted, or where there is no threat of incrimination in nowise supports the Court’s argument demeaning the privilege’s protection of privacy. The unavailability of the privilege in those cases only evidences that, as is the case with the First and Fourth Amendments, the protection of privacy afforded by the privilege is not absolute. The critical question then is the definition of the scope of privacy that is sheltered by the privilege.
*418History and principle teach that the privacy protected by the Fifth Amendment extends not just to the individual’s immediate declarations, oral or written, but also to his testimonial materials in the form of books and papers.3 “The right was originally a ‘right of silence’... only in the sense that legal process could not force incriminating statements from the defendant’s own lips. Beginning in the early eighteenth century the English courts widened that right to include protection against the necessity of producing books and documents that might tend to incriminate the accused. . . . Lord Mansfield summed up the law by declaring that the defendant, in a criminal case, could not be compelled to produce any incriminating documentary evidence ‘though he should hold it in his hands in Court.’ ” L. Levy, Origins of the Fifth Amendment 390 (1968).4 Thus, in recognizing *419the privilege’s protection of private books and papers, Boyd v. United States, 116 U. S., at 633, 634-635, was faithful to this historical conception of the privilege. Boyd was reaffirmed in this respect in Ballmann v. Fagin, 200 U. S. 186 (1906), which held that an individual could not be compelled to produce a personal cashbook containing incriminating evidence. Schmerber v. California, 384 U. S., at 761, most recently expressly held “that the privilege protects an accused . . . from being compelled to testify against himself, or otherwise provide the State with evidence of a testimonial or communicative nature . . . (Emphasis supplied.) Indeed, Boyd’s holding has often been reiterated without question. E. g., Bellis v. United States, 417 U. S. 85, 87 (1974); United States v. Calandra, 414 U. S. 338, 346 (1974); Couch v. United States, 409 U. S. 322 (1973); United States v. Wade, 388 U. S. 218, 221 (1967); Gilbert v. California, 388 U. S. 263, 266 (1967); Davis v. United States, 328 U. S. 582, 587-588 (1946); United States v. White, 322 U. S. 694, 698-699 (1944); Wheeler v. United States, 226 U. S. 478, 489 (1913); Wilson v. United States, 221 U. S. 361, 375 (1911); ICC v. Baird, 194 U. S. 25, 45 (1904). It may therefore be emphatically stated that until today, there was no room to doubt that it is the Fifth Amendment’s “historic function [to protect an individual] from compulsory incrimination through his *420own testimony or personal records.” United States v. White, supra, at 701 (emphasis supplied).
The common-law and constitutional extension of the privilege to testimonial materials, such as books and papers, was inevitable. An individuaFs books and papers are generally little more than an extension of his person. They reveal no less than he could reveal upon being questioned directly. Many of the matters within an individuaFs knowledge may as easily be retained within his head as set down on a scrap of paper. I perceive no principle which does not permit compelling one to disclose the contents of one’s mind but does permit compelling the disclosure of the contents of that scrap of paper by compelling its production. Under a contrary view, the constitutional protection would turn on fortuity, and persons would, at their peril, record their thoughts and the events of their lives. The ability to think private thoughts, facilitated as it is by pen and paper, and the ability to preserve intimate memories would be curtailed through fear that those thoughts or the events of those memories would become the subjects of criminal sanctions however invalidly imposed. Indeed, it was the very reality of those fears that helped provide the historical impetus for the privilege. See Boyd v. United States, supra, at 631-632; E. Griswold, The Fifth Amendment Today 8-9 (1955); 8 J. Wigmore, Evidence § 2250, pp. 277-281 (McNaughton rev. 1961); id., § 2251, pp. 313-314; McKay, Self-Incrimination and the New Privacy, 1967 Supreme Court Review 193, 212.5
*421The Court’s treatment of the privilege falls far short of giving it the scope required by history and our precedents.6 It is, of course, true “that the Fifth Amendment *422protects against 'compelled self-incrimination, not [the disclosure of] private information,’ ” ante, at 401, but it is also true that governmental compulsion to produce private information that might incriminate violates the protection of the privilege. Similarly, although it is necessary that the papers “contain no testimonial declarations by [the taxpayer]” in order for the privilege not to operate as a bar to production, ante, at 409, it does not fol*423low that papers are not “testimonial” and thus producible because they contain no declarations. And while it may be that the unavailability of the privilege depends on a showng that “the preparation of all of the papers sought in these cases was wholly voluntary,” ibid., again it does not follow that the protection is necessarily unavailable if the papers were prepared voluntarily, for it is the compelled production of testimonial evidence, not just the compelled creation of such evidence, against which the privilege protects.
Though recognizing that a subpoena served on a taxpayer involves substantial compulsion, the Court concludes that since the subpoena does not compel oral testimony or require the taxpayer to restate, repeat, or affirm the truth of the contents of the documents sought, compelled production of the documents by the taxpayer would not violate the privilege, even though the documents might incriminate the taxpayer. Ante, at 409. This analysis is patently incomplete: the threshold inquiry is whether the taxpayer is compelled to produce incriminating papers. That inquiry is not answered in favor of production merely because the subpoena requires neither oral testimony from nor affirmation of the papers' contents by the taxpayer. To be sure, the Court correctly observes that “[t]he taxpayer cannot avoid compliance with the subpoena merely by asserting that the item of evidence which he is required to produce contains incriminating writing, whether his own or that of someone else.” Ante, at 410 (emphasis supplied). For it is not enough that the production of a writing, or books and papers, is compelled. Unless those materials are such as to come within the zone of privacy recognized by the Amendment, the privilege against compulsory self-incrimination does not protect against their production.
*424We are not without guideposts for determining what books, papers, and writings come within the zone of privacy recognized by the Amendment. In Wilson v. United States, 221 U. S. 361 (1911), for example, the Court held that the Fifth Amendment did not protect against subpoenaing corporate records in the possession and control of the president of a corporation, even though the records might have incriminated him. Though the evidence was testimonial, though its production was compelled, and though it would have incriminated the party producing it, the Fifth Amendment was no bar. The Court recognized that the Amendment “ [undoubtedly . . . protected [the president] against the compulsory production of his private books and papers,” id., at 377, but with respect to corporate records, the Court held:
“[T]hey are of a character which subjects them to the. scrutiny demanded. . . . This was clearly implied in the Boyd Case where the fact that the papers involved were the private papers of the claimant was constantly emphasized. Thus, in the case of public records and official documents, made or kept in the administration of public office, the fact of actual possession or of lawful custody would not justify the officer in resisting inspection, even though the record was made by himself and would supply the evidence of his criminal dereliction.” Id., at 380 (emphasis in original).
Couch v. United States expressly held that the Fifth Amendment protected against the compelled production of testimonial evidence only if the individual resisting production had a reasonable expectation of privacy with respect to the evidence. 409 U. S., at 336. Couch relied on Perlman v. United States, 247 U. S. *4257 (1918), where the Court permitted the use against the defendant of documentary evidence belonging to him because “there was a voluntary exposition of the articles” rather than “an invasion of the defendant’s privacy.” Id., at 14. Under Couch, therefore, one criterion is whether or not the information sought to be produced has been disclosed to or was within the knowledge of a third party. 409 U. S., at 332-333. That is to say, one relevant consideration is the degree to which the paper holder has sought to keep private the contents of the papers he desires not to produce.
Most recently, Bellis v. United States, 417 U. S. 85 (1974), followed the approach taken in Wilson. Beilis held that the partner of a small law firm could not invoke the privilege against self-incrimination to justify his refusal to comply with a subpoena requiring production of the partnership’s financial records. Beilis stated: “It has long been established . . . that the Fifth Amendment privilege against compulsory self-incrimination protects an individual from compelled production of his personal papers and effects as well as compelled oral testimony.... The privilege applies to the business records of the sole proprietor or sole practitioner as well as to personal documents containing more intimate information about the individual’s private life.” 417 U. S., at 87-88. Bellis also recognized that the Court’s “decisions holding the privilege inapplicable to the records of a collective entity also reflect . . . the protection of an individual’s right to a ‘private enclave where he may lead a private life.’ . . . Protection of individual privacy was the major theme running through the Court’s decision in Boyd . . . and it was on this basis that the Court in Wilson distinguished the corporate records involved in that case from the private papers at issue in Boyd.” Id., at 91-92. “[C]or-*426porate records do not contain the requisite element of privacy or confidentiality essential for the privilege to attach.” Id., at 92. Beilis concluded that the same considerations which precluded reliance upon the privilege with respect to corporate records also precluded reliance upon it with respect to partnership records in the circumstances of that case.7
A precise cataloguing of private papers within the ambit of the privacy protected by the privilege is probably impossible. Some papers, however, do lend themselves to classification. See generally Comment, The Search and Seizure of Private Papers: Fourth and Fifth Amendment Considerations, 6 Loyola (LA) L. Rev. 274, 300-303 (1973). Production of documentary materials created or authenticated by a State or the Federal Government, such as automobile registrations or property deeds, would seem ordinarily to fall outside the protection of the privilege. They hardly reflect an extension of the person.
Economic and business records may present difficulty in particular cases. The records of business entities generally fall without the scope of the privilege. But, as noted, the Court has recognized that the privilege extends to the business records of the sole proprietor or practitioner. Such records are at least an extension of an aspect of a person’s activities, though con-*427cededly not the more intimate aspects of one’s life. Where the privilege would have protected one’s mental notes of his business affairs in a less complicated day and age, it would seem that that protection should not fall away because the complexities of another time compel one to keep business records. Cf. Olmstead v. United States, 277 U. S. 438, 474 (1928) (Brandeis, J., dissenting). Nonbusiness economic records in the possession of an individual, such as canceled checks or tax records, would also seem to be protected. They may provide clear insights into a person’s total lifestyle. They are, however, like business records and the papers involved in these cases, frequently, though not always, disclosed to other parties; and disclosure, in proper eases, may foreclose reliance upon the privilege. Personal letters constitute an integral aspect of a person’s private enclave. And while letters, being necessarily interpersonal, are not wholly private, their peculiarly private nature and the generally narrow extent of their disclosure would seem to render them within the scope of the privilege. Papers in the nature of a personal diary are a fortiori protected under the privilege.
The Court’s treatment in the instant eases of the question whether the evidence involved here is within the protection of the privilege is, with all respect, most inadequate. The gaping hole is in the omission of any reference to the taxpayer’s privacy interests and to whether the subpoenas impermissibly invade those interests. The observations that the “accountant’s workpapers are not the taxpayer’s” and “were not prepared by the taxpayer,” ante, at 409, touch on matters relevant to the taxpayer’s expectation of privacy, but do not of themselves determine the availability of the privilege. Wilson v. United States, 221 U. S., at 378, stated: “[T]he mere fact that *428the appellant himself wrote, or signed, the [documents], neither conditioned nor enlarged his privilege. Where one's private documents would tend to incriminate him, the privilege exists although they were actually written by another person.”8 Thus, although “[t]he fact that the documents may have been written by the person asserting the privilege is insufficient to trigger the privilege,” ante, at 410 n. 11, and “the fact that it was written by him is not controlling ibid., this is not to say that the privilege is available only as to documents written by him. For the reasons I have stated at the outset, however, I do not believe that the evidence involved in these cases falls within the scope of privacy protected by the Fifth Amendment.
II
I also question the Court’s treatment of the question whether the act of producing evidence is “testimonial.” I agree that the act of production implicitly admits the existence of the evidence requested and possession or control of that evidence by the party producing it. It also implicitly authenticates the evidence as that identified in the order to compel. I disagree, however, that implicit admission of the existence and possession or control of the papers in this case is not “testimonial” merely because the Government could readily have otherwise proved existence and possession or control in these cases. *429I know of no Fifth Amendment principle which makes the testimonial nature of evidence and, therefore, one’s protection against incriminating himself, turn on the strength of the Government’s case against him.
Nor do I consider the taxpayers’ implicit authentication an insubstantial threat of self-incrimination. Actually, authentication of the papers as those described in the subpoenas establishes the papers as the taxpayers’, thereby supplying an incriminatory link in the chain of evidence against them. It is not the less so because the taxpayers’ accountants may also provide the link, since the protection against self-incrimination cannot, I repeat, turn on the strength of the Government’s case.
This Court’s treatment of handwriting exemplars is not supportive of its position. See Gilbert v. California, 388 U. S. 263 (1967). The Court has only recognized that “[a] mere handwriting exemplar . . . , like the voice or body itself, is an identifying physical characteristic outside its protection.” Id., at 266-267. It is because handwriting exemplars are viewed as strictly nontestimonial, not because they are insufficiently testimonial, that the Fifth Amendment does not protect against their compelled production. Also not supportive of the Court’s position is the principle that the custodian of documents of a collective entity is not protected from the act of producing those documents. Nothing in the language of those cases, either expressly or impliedly, indicates that the act of production with respect to the records of business entities is insufficiently testimonial for purposes of the Fifth Amendment. At most, those issues, though considered, were disposed of on the ground, not that production was insufficiently testimonial, but that one in control of the records of an artificial organiza*430tion undertakes an obligation with respect to those records foreclosing any exercise of his privilege.9
For example, the Court’s notation that “[s] pedal problems of privacy which might be presented by subpoena of a diary . . . are not involved here,” ante, at 401 n. 7, is only made in the context of discussion of the Fourth Amendment and thus may readily imply that even a subpoena of a personal diary containing forthright confessions of crime may not be resisted on grounds of the privilege.
“The privilege against self-incrimination is a specific provision of which it is peculiarly true that 'a page of history is worth a volume of logic.'” Ullmann v. United States, 350 U. S. 422, 438 (1956) (Frankfurter, J.). “The previous history of the right, both in England and America, proves that it was not bound by rigid definition.” L. Levy, Origins of the Fifth Amendment 428 (1968).
Indeed, Schmerber v. California, 384 U. S. 757, 764 (1966), held:
“Some tests seemingly directed to obtain ‘physical evidence,’ for example, lie detector tests measuring changes in body function during interrogation, may actually be directed to eliciting responses which are essentially testimonial. To compel a person to submit to resting in which an effort will be made to determine his guilt or innocence on the basis of physiological responses, whether willed or not, is to evoke the spirit and history of the Fifth Amendment. Such situations call to mind the principle that the protection of the privilege ‘is as broad as the mischief against which it seeks to guard.’. ..”
“The language of the Constitution cannot be interpreted safely except by reference to the common law and to British institutions as they were when the instrument was framed and adopted.” Ex parte Grossman, 267 U. S. 87, 108-109 (1925). But, “the common law rule invoked shall be one not rejected by our ancestors as unsuited to their civil or political conditions.” Grosjean v. American Press Co., 297 U. S. 233, 249 (1936). Without a doubt, the common-law privilege against self-incrimination in England extended to protection against the production of incriminating personal papers prior to the adoption of the United States Constitution. See, e. g., *419Roe v. Harvey, 98 Eng. Rep. 302, 305 (K. B. 1769); King v. Heydon, 96 Eng. Rep. 195 (K. B. 1762); King v. Purnell, 95 Eng. Rep. 595, 597 (K. B. 1748); King v. Cornelius, 93 Eng. Rep. 1133, 1134 (K. B. 1744); Queen v. Mead, 92 Eng. Rep. 119 (K. B. 1703); King v. Worsenham, 91 Eng. Rep. 1370 (K. B. 1701). The significance of this English development on the construction of our Constitution is not in any way diminished by this country’s experience with the privilege prior to the Constitution’s adoption. See Levy, supra, n. 2, at 368-404.
“And any compulsory discovery by extorting the party's oath, or compelling the production of his private books and papers, to convict him of crime, or to forfeit his property, is contrary to the principles of a free government. It is abhorrent to the instincts of an Englishman; it is abhorrent to the instincts of an American. It may suit the purposes of despotic power; but it cannot abide the *421pure atmosphere of political liberty and personal freedom.” Boyd v. United States, 116 U. S., at 631-632.
The proposition, ante, at 409, that Boyd’s holding ultimately rested on the Fourth Amendment could not be more incorrect. Boyd did observe that the purposes to be served by the Fourth and Fifth Amendments shed light on each other, 116 U. S., at 633, but the holdings that the compelled production of the papers involved there violated the Fourth and Fifth Amendments were independent of each other. In holding that “a compulsory production of the private books and papers of the owner of goods sought to be forfeited in such a suit is compelling him to be a witness against himself, within the meaning of the Fifth Amendment to the Constitution, and is the equivalent of a search and seizure — and an unreasonable search and seizure — within the meaning of the Fourth Amendment,” id., at 634-635, the Court plainly did not make the Fourth Amendment violation a predicate, let alone an essential predicate, for its holding that there was also a Fifth Amendment violation. The Court is incorrect in suggesting that “the rule against compelling production of private papers rested on the proposition that seizures of or subpoenas for 'mere evidence/ including documents, violated the Fourth Amendment and therefore also transgressed the Fifth.” Ante, at 409. The relation of the Fourth Amendment to the Fifth Amendment violation in United States v. Lefkowitz, 285 U. S. 452 (1932); Agnello v. United States, 269 U. S. 20 (1925); and Gouled v. United States, 255 U. S. 298 (1921), was merely that the illegal searches and seizures in those cases were held to establish the element of compulsion essential to a Fifth Amendment violation. See ante, at 399-400, n. 5. Even if the Fourth Amendment violations were now held not to establish the element of Fifth Amendment compulsion, it, of course, would not follow that the Fifth Amendment’s protection against compelled production of incriminating private papers is lost.
Furthermore, that purely evidentiary material may have been seized in those cases was neither relied upon to establish the Fourth Amendment violations nor, in turn, to establish the Fifth Amendment violations. Indeed, in Agnello, contraband, not mere evidence, *422was illegally seized. Subsequent decisions modifying the “mere evidence” rule, therefore, have left untouched the Fifth Amendment’s prohibition against the compelled production of incriminating testimonial evidence. Indeed, citing Warden v. Hayden, 387 U. S. 294 (1967), the Court notes, that the question is open whether the legal search and seizure of some forms of testimonial evidence would violate the Fifth Amendment, ante, at 407 n. 9. Warden v. Hayden observed: “The items of clothing involved in this case are not ‘testimonial’ or ‘communicative’ in nature, and their introduction therefore did not compel respondent to become a witness against himself in violation of the Fifth Amendment. . . . This case thus does not require that we consider whether there are items of evidential value whose very nature precludes them from being the object of a reasonable search and seizure.” 387 U. S., at 302-303. That observation was plainly addressed not to application of the Fourth Amendment but to application of the Fifth.
Contrary to the Court’s intimations, ante, at 407-408, neither Katz v. United States, 389 U. S. 347 (1967); Osborn v. United States, 385 U. S. 323 (1966); nor Berger v. New York, 388 U. S. 41 (1967), all involving the Fourth Amendment, lends support to an argument that the Fifth Amendment would not protect the seizure of the private papers of a person suspected of crime. Fifth Amendment challenges to the seizure and use of private papers were not involved in those cases.
The grudging scope the Court today gives the privilege against self-incrimination is made evident by its observation that “[i]n the case of a documentary subpoena the only thing compelled is the act of producing the document .. . .” Ante, at 410 n. 11. Obviously disclosure or production of testimonial evidence is also compelled, and the heart of the protection of the privilege is in its safeguarding against compelled disclosure or production of that evidence.
With respect to a partnership invoice, it thus seems fair to say, as the Court does, ante, at 408, “that under [Bellis] the precise claim sustained in Boyd would now be rejected for reasons not there considered.” Bellis, however, took care to point out: “We do not believe the Court in Boyd can be said to have decided the issue presented today,” 417 U. S., at 95 n. 2, thereby leaving unaltered Boyd’s more general or “imprecise” holding protecting against the compelled production of private papers.
Similarly, United States v. Nobles, 422 U. S. 225 (1975), held that the Fifth Amendment did not bar production of a defense investigator’s summaries of interviews with witnesses. The Court carefully noted, however, that there was no indication that the summaries contained any information conveyed by the defendant to the investigator. Id., at 234.
Individuals acting as representatives of a collective group “assume the rights, duties and privileges of the artificial entity or association of which they are agents or officers and they are bound by its obligations.” United States v. White, 322 U. S. 694, 699 (1944). “In view of the inescapable fact that an artificial entity can only act to produce its records through its individual officers or agents, recognition of the individual’s claim of privilege with respect to the financial records of the organization would substantially undermine the unchallenged rule that the organization itself is not entitled to claim any Fifth Amendment privilege, and largely frustrate legitimate governmental regulation of such organizations.” Bellis v. United States, 417 U. S., at 90. Indeed, in one of the more recent corporate records cases, Curcio v. United States, 354 U. S. 118, 125 (1957), the Court expressly recognized that “[t]he custodian’s act of producing books or records in response to a subpoena duces tecum is itself a representation that the documents produced are those demanded by the subpoena.” The Court in Curdo, however, apparently did not note any self-incrimination problem because of the undertaking by the custodian with respect to the documents. (One charged with failure to comply with an order to produce, however, may not thereafter be compelled to testify as to the existence or his control of the documents. See Curcio v. United States, supra.) In the present cases, of course, the taxpayers are not representatives of any artificial entity and have not undertaken any obligation with respect to that entity or its documents. They have stipulated, however, that the documents involved here exist and are those described in the subpoenas, thereby obviating any problem as to self-incrimination in these cases resulting from the act of production itself.