JUSTICE O'CONNOR delivered the opinion of the Court.
At issue in this case are several questions arising from the application of the National Labor Relations Act (NLRA or Act) to an employer's treatment of its undocumented alien employees. We first determine whether the National Labor Relations Board (NLRB or Board) may properly find that an employer engages in an unfair labor practice by reporting to the Immigration and Naturalization Service (INS) certain employees known to be undocumented aliens in retaliation for their engaging in union activity, thereby causing their immediate departure from the United States. We then address the validity of the Board's remedial order as modified by the Court of Appeals.
I
Petitioners are two small leather processing firms located in Chicago that, for purposes of the Act, constitute a single integrated employer. In July, 1976, a union organization drive was begun. Eight employees signed cards authorizing the Chicago Leather Workers Union, Local 431, Amalgamated Meatcutters and Butcher Workmen of North America (Union), to act as their collective bargaining representative. Of the 11 employees then employed by petitioners, most were Mexican nationals present illegally in the United States without visas or immigration papers authorizing them to work. The Union ultimately prevailed in a Board election conducted on December 10, 1976.
Two hours after the election, petitioners' president, John Surak, addressed a group of employees, including some of the undocumented aliens involved in this case. He asked the employees why they had voted for the Union and cursed them for doing so. He then inquired as to whether they had valid immigration papers. Many of the employees indicated that they did not.
Petitioners filed with the Board objections to the election, arguing that six of the seven eligible voters were illegal aliens. Surak executed an accompanying affidavit which stated that he had known about the employees' illegal presence in this country for several months prior to the election. On January 19, 1977, the Board's Acting Regional Director notified petitioners that their objections were overruled and that the Union would be certified as the employees' collective bargaining representative. The next day, Surak sent a letter to the INS asking that the agency check into the status of a number of petitioners' employees as soon as possible. In response to the letter, INS agents visited petitioners' premises on February 18, 1977, to investigate the immigration status of all Spanish-speaking employees. The INS agents discovered that five employees were living and working illegally in the United States, and arrested them. Later that day, each employee executed an INS form, acknowledging illegal presence in the country and accepting INS's grant of voluntary departure as a substitute for deportation. By the end of the day, all five employees were on a bus ultimately bound for Mexico.
On February 22 and March 23, 1977, the Board's Acting Regional Director issued complaints alleging that petitioners had committed various unfair labor practices. On March 29, 1977, petitioners sent letters to the five employees who had returned to Mexico offering to reinstate them, provided that doing so would not subject Sure-Tan to any violations of United States immigration laws. The offers were to remain open until May 1, 1977.
The unfair labor practice charges were heard by an Administrative Law Judge (ALJ), whose findings and conclusions as to the merits of the complaints were affirmed and adopted by the Board. Specifically, the Board affirmed the ALJ's conclusion that petitioners had violated §§ 8(a)(1) and (3) [ Footnote 1 ] by requesting the INS to investigate the status of their Mexican employees "solely because the employees supported the Union" and "with full knowledge that the employees in question had no papers or work permits." Sure-Tan, Inc., 234 N.L.R.B. 1187 (1978). The Board, therefore, agreed with the ALJ's finding that
the discriminatees' subsequent deportation was the proximate result of the discriminatorily motivated action by [petitioners], and constitutes a constructive discharge.
Id. at 1191. [ Footnote 2 ]
As a remedy for the § 8(a)(3) violations, the Board adopted the ALJ's recommendation that petitioners be ordered to cease and desist from their various unfair labor practices, including notifying the INS of their employees' status because of the employees' support of the Union. However, the Board declined to adopt the ALJ's specific recommendations as to the appropriate remedy. The ALJ had recommended that petitioners be ordered to offer the discharged employees reinstatement and that the offers be held open for six months. In addition, the ALJ had concluded that since, under past Board precedent, backpay is normally tolled during those periods in which employees are not available for employment, an ordinary backpay award could not be ordered in this case. Nevertheless, the ALJ had invited the Board to consider awarding backpay for a minimum 4-week period both to provide some measure of relief to the illegally discharged employees and to deter future violations of the NLRA.
The Board, however, concluded that the ALJ's analysis of the remedy was "unnecessarily speculative." 234 N.L.R.B. at 1187. Since the record contained no evidence that the employees had not since returned to the United States, the Board modified the ALJ's order by substituting the "conventional remedy of reinstatement with backpay," thereby leaving until subsequent compliance proceedings the determination whether the employees had in fact been available for work. [ Footnote 3 ] Ibid.
On appeal, the Court of Appeals enforced the Board's order. 672 F.2d 592 (CA7 1982). The court fully agreed that petitioners had violated the NLRA by constructively discharging their undocumented alien employees. It also concurred in the Board's judgment that the usual remedies of reinstatement and backpay were appropriate in these circumstances. The Court of Appeals did, however, modify the Board's order in several significant respects. First, it concluded that reinstatement would be proper only if the discharged employees were legally present and free to be employed in the United States when they presented themselves for reinstatement. The court also decided that the reinstatement offers in their present form were deficient, since they did not allow a reasonable time for the employees to make arrangements for legal reentry. The court therefore ordered that the offers be left open for a period of four years. It further concluded that the offers must be written in Spanish, and delivered so as to allow for verification of receipt.
As for backpay, the court required that the discharged employees should be deemed unavailable for work during any period when they were not legally entitled to be present and employed in the United States. Recognizing that the discharged employees would most likely not have been lawfully available for employment, and so would receive no backpay award at all, the court decided that
it would better effectuate the policies of the Act to set a minimum amount of backpay which the employer must pay in any event, because it was his discriminatory act which caused these employees to lose their jobs.
Id. at 606. Believing that six months' backpay would be the minimum amount appropriate for this purpose, the court suggested that the Board consider this remedy. The Board accepted the court's suggestion, and the final judgment order approved by the court included the minimum award of six months' backpay. [ Footnote 4 ] We granted certiorari, 460 U.S. 1021 (1983). We now affirm the judgment of the Court of Appeals insofar as it determined that petitioners violated the Act by constructively discharging their undocumented alien employees, but reverse the judgment as to some of the remedies ordered and direct that the case be remanded to the Board.
II
A
We first consider the predicate question whether the NLRA should apply to unfair labor practices committed against undocumented aliens. The Board has consistently held that undocumented aliens are "employees" within the meaning of § 2(3) of the Act. [ Footnote 5 ] That provision broadly provides that "[t]he term employee' shall include any employee," 29 U.S.C. § 152(3), subject only to certain specifically enumerated exceptions. Ibid. Since the task of defining the term "employee" is one that "has been assigned primarily to the agency created by Congress to administer the Act," NLRB v. Hearst Publications, Inc., 322 U. S. 111, 322 U. S. 130 (1944), the Board's construction of that term is entitled to considerable deference, and we will uphold any interpretation that is reasonably defensible. See, e.g., Ford Motor Co. v. NLRB, 441 U. S. 488, 441 U. S. 496 -497 (1979); NLRB v. Iron Workers, 434 U. S. 335, 434 U. S. 350 (1978); NLRB v. Erie Resistor Corp., 373 U. S. 221, 373 U. S. 236 (1963).
The terms and policies of the Act fully support the Board's interpretation in this case. The breadth of § 2(3)'s definition is striking: the Act squarely applies to "any employee." The only limitations are specific exemptions for agricultural laborers, domestic workers, individuals employed by their spouses or parents, individuals employed as independent contractors or supervisors, and individuals employed by a person who is not an employer under the NLRA. See 29 U.S.C. § 152(3). Since undocumented aliens are not among the few groups of workers expressly exempted by Congress, they plainly come within the broad statutory definition of "employee."
Similarly, extending the coverage of the Act to such workers is consistent with the Act's avowed purpose of encouraging and protecting the collective bargaining process. See Hearst Publications, Inc., supra, at 322 U. S. 126. As this Court has previously recognized:
[A]cceptance by illegal aliens of jobs on substandard terms as to wages and working conditions can seriously depress wage scales and working conditions of citizens and legally admitted aliens; and employment of illegal aliens under such conditions can diminish the effectiveness of labor unions.
De Canas v. Bica, 424 U. S. 351, 424 U. S. 356 -357 (1976). If undocumented alien employees were excluded from participation in union activities and from protections against employer intimidation, there would be created a subclass of workers without a comparable stake in the collective goals of their legally resident coworkers, thereby eroding the unity of all the employees and impeding effective collective bargaining. See NLRB v. Jones & Laughlin Steel Corp., 301 U. S. 1, 301 U. S. 33 (1937). Thus, the Board's categorization of undocumented aliens as protected employees furthers the purposes of the NLRA.
B
Counterintuitive though it may be, we do not find any conflict between application of the NLRA to undocumented aliens and the mandate of the Immigration and Nationality Act (INA), 66 Stat. 163, as amended, 8 U.S.C. § 1101 et seq. This Court has observed that
[t]he central concern of the INA is with the terms and conditions of admission to the country and the subsequent treatment of aliens lawfully in the country.
De Canas v. Bica, 424 U.S. at 424 U. S. 359. The INA evinces "at best, evidence of a peripheral concern with employment of illegal entrants." Id. at 424 U. S. 360. For whatever reason, Congress has not adopted provisions in the INA making it unlawful for an employer to hire an alien who is present or working in the United States without appropriate authorization. While it is unlawful to "concea[l], harbo[r], or shiel[d] from detection" any alien not lawfully entitled to enter or reside in the United States, see 8 U.S.C. § 1324(a)(3), an explicit proviso to the statute explains that
employment (including the usual and normal practices incident to employment) shall not be deemed to constitute harboring.
Ibid. See De Canas v. Bica, supra, at 424 U. S. 360, and n. 9. Moreover, Congress has not made it a separate criminal offense for an alien to accept employment after entering this country illegally. See 119 Cong.Rec. 14184 (1973) (remarks of Rep. Dennis). Since the employment relationship between an employer and an undocumented alien is hence not illegal under the INA, there is no reason to conclude that application of the NLRA to employment practices affecting such aliens would necessarily conflict with the terms of the INA.
We find persuasive the Board's argument that enforcement of the NLRA with respect to undocumented alien employees is compatible with the policies of the INA. A primary purpose in restricting immigration is to preserve jobs for American workers; immigrant aliens are therefore admitted to work in this country only if they "will not adversely affect the wages and working conditions of the workers in the United States similarly employed." 8 U.S.C. § 1182(a)(14). See S.Rep. No. 748, 89th Cong., 1st Sess., 15 (1965). Application of the NLRA helps to assure that the wages and employment conditions of lawful residents are not adversely affected by the competition of illegal alien employees who are not subject to the standard terms of employment. If an employer realizes that there will be no advantage under the NLRA in preferring illegal aliens to legal resident workers, any incentive to hire such illegal aliens is correspondingly lessened. In turn, if the demand for undocumented aliens declines, there may then be fewer incentives for aliens themselves to enter in violation of the federal immigration laws. The Board's enforcement of the NLRA as to undocumented aliens is therefore clearly reconcilable with, and serves the purposes of, the immigration laws as presently written.
III
Accepting the premise that the provisions of the NLRA are applicable to undocumented alien employees, we must now address the more difficult issue whether, under the circumstances of this case, petitioners committed an unfair labor practice by reporting their undocumented alien employees to the INS in retaliation for participating in union activities. Section 8(a)(3) makes it an unfair labor practice for an employer
by discrimination in regard to hire or tenure of employment or any term or condition of employment to encourage or discourage membership in any labor organization.
29 U.S.C. § 158(a)(3). The Board, with the approval of lower courts, has long held that an employer violates this provision not only when, for the purpose of discouraging union activity, it directly dismisses an employee, but also when it purposefully creates working conditions so intolerable that the employee has no option but to resign -a so-called "constructive discharge." See, e.g., NLRB v. Haberman Construction Co., 641 F.2d 351, 358 (CA5 1981) (en banc); Cartwright Hardware Co. v. NLRB, 600 F.2d 268, 270 (CA10 1979); J. P. Stevens & Co. v. NLRB, 461 F.2d 490, 494 (CA4 1972); NLRB v. Holly Bra of California, Inc., 405 F.2d 870, 872 (CA9 1969); Atlas Mills, Inc., 3 N.L.R.B. 10, 17 (1937). See also 3 T. Kheel, Labor Law § 12.05[1][a] (1982).
Petitioners do not dispute that the antiunion animus element of this test was, as expressed by the lower court, "flagrantly met." 672 F.2d at 601.
The record is replete with examples of Sure-Tan's blatantly illegal course of conduct to discourage its employees from supporting the Union.
Id. at 601-602. Petitioners contend, however, that their conduct in reporting the undocumented alien workers did not force the workers' departure from the country; instead, they argue, it was the employees' status as illegal aliens that was the actual "proximate cause" of their departure. See Brief for Petitioners 13-15.
This argument is unavailing. According to testimony by an INS agent before the ALJ, petitioners' letter was the sole cause of the investigation during which the employees were taken into custody. This evidence was undisputed by petitioners, and amply supports the ALJ's conclusion that "but for [petitioners'] letter to Immigration, the discriminatees would have continued to work indefinitely." 234 N.L.R.B. at 1191. And there can be little doubt that Surak foresaw precisely this result when, having known about the employees' illegal status for some months, he notified the INS only after the Union's electoral victory was assured. See supra at 467 U. S. 887 ; 672 F.2d at 601.
We observe that the Board quite properly does not contend that an employer may never report the presence of an illegal alien employee to the INS. See, e.g., Bloom/Art Textiles, Inc., 225 N.L.R.B. 766 (1976) (no violation of Act for employer to discharge illegal alien who was a union activist where the evidence showed that the reason for the discharge was not the employee's protected collective activities, but the employer's concern that employment of the undocumented worker violated state law). The reporting of any violation of the criminal laws is conduct which ordinarily should be encouraged, not penalized. See In re Quarles, 158 U. S. 532, 158 U. S. 535 (1895). [ Footnote 6 ] It is only when the evidence establishes that the reporting of the presence of an illegal alien employee is in retaliation for the employee's protected union activity that the Board finds a violation of § 8(a)(3). Absent this specific finding of antiunion animus, it would not be an unfair labor practice to report or discharge an undocumented alien employee. See Bloom/Art Textiles, Inc., supra. Such a holding is consistent with the policies of both the INA and the NLRA.
Finally, petitioners claim that this Court's recent decision in Bill Johnson's Restaurants, Inc. v. NLRB, 461 U. S. 731 (1983), mandates the conclusion that their request for enforcement of the federal immigration laws is an aspect of their First Amendment right "to petition the Government for a redress of grievances," and therefore may not be burdened under the guise of enforcing the NLRA. [ Footnote 7 ] In Bill Johnson's Restaurants, the Court held that an employer's filing of a state court suit against its employees seeking damages and injunctive relief for libelous statements and injury to its business is not an enjoinable unfair labor practice unless the suit is filed for retaliatory purposes and lacks a reasonable basis. The Court stressed that the right of access to courts for redress of wrongs is an aspect of the First Amendment right to petition the government, concluding that the NLRA must be construed in such a way as to be "sensitive" to these First Amendment values. Id. at 461 U. S. 741. The Court also noted that the States had a compelling interest in maintaining domestic peace by providing employers with such civil remedies for tortious conduct during labor disputes. If the Board were allowed to enjoin a state lawsuit simply because of retaliatory motive, the employer would "be totally deprived of a remedy for an actual injury," and the strong state interest in providing for such redress would therefore be undermined. Id. at 461 U. S. 742.
The reasoning of Bill Johnson's Restaurants simply does not apply to petitioners' situation. The employer in that case, though similarly motivated by a desire to discourage the exercise of NLRA rights, was asserting in state court a personal interest in its own reputation that was protected by state law. If the Court had upheld the Board in the case, it would have left the employer with no forum in which to pursue a remedy for an "actual injury." Id. at 461 U. S. 741. The First Amendment right protected in Bill Johnson's Restaurants is plainly a "right of access to the courts… for redress of alleged wrongs.'" Ibid. Petitioners in this case, however, have not suffered a comparable, legally protected injury at the hands of their employees. Petitioners did not invoke the INS administrative process in order to seek the redress of any wrongs committed against them. Cf. California Motor Transport Co. v. Trucking Unlimited, 404 U. S. 508 (1972). Indeed, private persons such as petitioners have no judicially cognizable interest in procuring enforcement of the immigration laws by the INS. Cf. Linda R. S. v. Richard D., 410 U. S. 614, 410 U. S. 619 (1973).
Finally, Bill Johnson's Restaurants was concerned about whether the Board's interpretation of the NLRA would work to preempt the State from providing civil remedies for conduct touching interests " deeply rooted in local feeling and responsibility.'" 461 U.S. at 461 U. S. 741 (quoting San Diego Building Trades Council v. Garmon,359 U. S. 236,359 U. S. 244(1959)). Here, where there is no conflict between the Board's unfair labor practice finding and any asserted state interest, such federalism concerns are simply not at stake. In short,Bill Johnson's Restaurantswill not support petitioners' efforts to avoid their obligations under the NLRA by reporting their employees to the INS.
IV
There remains for us to consider petitioners' challenges to the remedial order entered in this case. Petitioners attack those portions of the Court of Appeals' order which modified the Board's original order by providing for an irreducible minimum of six months' backpay for each employee, and by detailing the language, acceptance period, and verification method of the reinstatement offers. [ Footnote 8 ] We find that the Court of Appeals exceeded its narrow scope of review in imposing both these modifications.
A
Section 10(c) of the Act empowers the Board, when it finds that an unfair labor practice has been committed, to issue an order requiring the violator to
cease and desist from such unfair labor practice, and to take such affirmative action including reinstatement of employees with or without backpay, as will effectuate the policies
of the NLRA. 29 U.S.C. § 160(c). The Court has repeatedly interpreted this statutory command as vesting in the Board the primary responsibility and broad discretion to devise remedies that effectuate the policies of the Act, subject only to limited judicial review. See, e.g., NLRB v. J. H. Rutter-Rex Mfg. Co., 396 U. S. 258, 396 U. S. 262 -263 (1969); Fibreboard Paper Products Corp. v. NLRB, 379 U. S. 203, 379 U. S. 216 (1964); Phelps Dodge Corp. v. NLRB, 313 U. S. 177, 313 U. S. 194 (1941). Although the courts of appeals have power under the Act "to make and enter a decree… modifying, and enforcing as so modified" the orders of the Board, 29 U.S.C. §§ 160(e), (f), they should not substitute their judgment for that of the Board in determining how best to undo the effects of unfair labor practices:
Because the relation of remedy to policy is peculiarly a matter for administrative competence, courts must not enter the allowable area of the Board's discretion, and must guard against the danger of sliding unconsciously from the narrow confines of law into the more spacious domain of policy.
Phelps Dodge Corp., supra, at 313 U. S. 194. See also NLRB v. Seven-Up Bottling Co., 344 U. S. 344, 344 U. S. 346 (1953) (power to fashion remedies "is for the Board to wield, not for the courts").
Here, the Court of Appeals impermissibly expanded the Board's original order to provide that each discriminatee would receive backpay for at least six months on the ground that "six months is a reasonable assumption" as to the
minimum [time] during which the discriminatees might reasonably have remained employed without apprehension by INS, but for the employer's unfair labor practice.
672 F.2d at 606. We agree with petitioners that this remedy ordered by the Court of Appeals exceeds the limits imposed by the NLRA. [ Footnote 9 ]
Not only did the court overstep the limits of its own reviewing authority, see NLRB v. Seven-Up Bottling Co., supra, at 344 U. S. 346 -347, [ Footnote 10 ] but it also effectively compelled the Board to take action that simply does not lie within the Board's own powers. Under § 10(c), the Board's authority to remedy unfair labor practices is expressly limited by the requirement that its orders "effectuate the policies of the Act." Although this rather vague statutory command obviously permits the Board broad discretion, at a minimum, it encompasses the requirement that a proposed remedy be tailored to the unfair labor practice it is intended to redress. Quite early on, the Court established that "the relief which the statute empowers the Board to grant is to be adapted to the situation which calls for redress." NLRB v. MacKay Radio & Telegraph Co., 304 U. S. 333, 304 U. S. 348 (1938). See D. McDowell & K. Huhn, NLRB Remedies for Unfair Labor Practices 8-15 (1976). Of course, the general legitimacy of the backpay order as a means to restore the situation "as nearly as possible, to that which would have obtained but for the illegal discrimination," Phelps Dodge Corp., 313 U.S. at 313 U. S. 194, is by now beyond dispute. Yet it remains a cardinal, albeit frequently unarticulated, assumption that a backpay remedy must be sufficiently tailored to expunge only the actual, and not merely speculative, consequences of the unfair labor practices. Id. at 313 U. S. 198 ("[O]nly actual losses should be made good…"). To this end, we have, for example, required that the Board give due consideration to the employee's responsibility to mitigate damages in fashioning an equitable backpay award. See, e.g., NLRB v. Seven-Up Bottling Co., supra, at 344 U. S. 346 ; Phelps Dodge Corp. v. NLRB, supra, at 313 U. S. 198. Likewise, the Board's own longstanding practice has been to deduct from the backpay award any wages earned in the interim in another job, see Pennsylvania Greyhound Lines, Inc., 1 N.L.R.B. 1, 51 (1935), enf'd, 91 F.2d 178 (CA3 1937), rev'd on other grounds, 303 U. S. 261 (1938).
By contrast, the Court of Appeals' award of a minimum amount of backpay in this case is not sufficiently tailored to the actual, compensable injuries suffered by the discharged employees. The court itself admitted that, although it sought to recompense the discharged employees for their lost wages, the actual 6-month period selected was "obviously conjectural." 672 F.2d at 606. The court's imposition of this minimum backpay award in the total absence of record evidence as to the circumstances of the individual employees constitutes pure speculation, and does not comport with the general reparative policies of the NLRA. [ Footnote 11 ]
We generally approve the Board's original course of action in this case by which it ordered the conventional remedy of reinstatement with backpay, leaving until the compliance proceedings more specific calculations as to the amounts of backpay, if any, due these employees. This Court and other lower courts have long recognized the Board's normal policy of modifying its general reinstatement and backpay remedy in subsequent compliance proceedings as a means of tailoring the remedy to suit the individual circumstances of each discriminatory discharge. See NLRB v. J. H. Rutter-Rex Mfg. Co., 396 U.S. at 396 U. S. 260 ; Nathanson v. NLRB, 344 U. S. 25, 344 U. S. 29 -30 (1952); Trico Products Corp. v. NLRB, 489 F.2d 347, 353-354 (CA2 1973). Cf. Teamsters v. United States, 431 U. S. 324, 431 U. S. 371 (1977) (individual Title VII claims to be resolved at remedial hearings held by District Court on remand). These compliance proceedings provide the appropriate forum where the Board and petitioners will be able to offer concrete evidence as to the amounts of backpay, if any, to which the discharged employees are individually entitled. See NLRB v. Mastro Plastics Corp., 354 F.2d 170 (CA2 1965), cert. denied, 384 U.S. 972 (1966); 3 NLRB Casehandling Manual § 10656 et seq. (1977) (preparation of backpay specification).
Nonetheless, as the Court of Appeals recognized, the implementation of the Board's traditional remedies at the compliance proceedings must be conditioned upon the employees' legal readmittance to the United States. In devising remedies for unfair labor practices, the Board is obliged to take into account another "equally important Congressional objectiv[e]," Southern S.S. Co. v. NLRB, 316 U. S. 31, 316 U. S. 47 (1942) -to-wit, the objective of deterring unauthorized immigration that is embodied in the INA. By conditioning the offers of reinstatement on the employees' legal reentry, a potential conflict with the INA is thus avoided. Similarly, in computing backpay, the employees must be deemed "unavailable" for work (and the accrual of backpay therefore tolled) during any period when they were not lawfully entitled to be present and employed in the United States. Cf. 3 NLRB Casehandling Manual §§ 10612, 10656.9 (1977). [ Footnote 12 ]
The Court of Appeals assumed that, under these circumstances, the employees would receive no backpay, and so awarded a minimum amount of backpay that would effectuate the underlying purposes of the Act by providing some relief to the employees, as well as a financial disincentive against the repetition of similar discriminatory acts in the future. 672 F.2d at 606. We share the Court of Appeals' uncertainty concerning whether any of the discharged employees will be able either to enter the country lawfully to accept the reinstatement offers or to establish at the compliance proceedings that they were lawfully available for employment during the backpay period. The probable unavailability of the Act's more effective remedies in light of the practical workings of the immigration laws, however, simply cannot justify the judicial arrogation of remedial authority not fairly encompassed within the Act. Any perceived deficiencies in the NLRA's existing remedial arsenal can only be addressed by congressional action. [ Footnote 13 ] By directing the Board to impose a minimum backpay award without regard to the employees' actual economic losses or legal availability for work, the Court of Appeals plainly exceeded its limited authority under the Act. [ Footnote 14 ]
B
The Court of Appeals similarly exceeded its limited authority of judicial review by modifying the Board's order so as to require petitioners to draft the reinstatement offers in Spanish, and to ensure verification of receipt. While such requirements appear unobjectionable in that they constitute a rather trivial burden, they represent just the type of informed judgment which calls for the Board's superior expertise and long experience in handling specific details of remedial relief. See, e.g., NLRB v. J. Weingarten, Inc., 420 U. S. 251, 420 U. S. 266 -267 (1975); NLRB v. Erie Resistor Corp., 373 U.S. at 373 U. S. 236. If the court believed that the Board had erred in failing to impose such requirements, the appropriate course was to remand back to the Board for reconsideration. NLRB v. Food Store Employees, 417 U. S. 1 (1974). Such action
best respects the congressional scheme investing the Board, and not the courts, with broad powers to fashion remedies that will effectuate national labor policy.
Id. at 417 U. S. 10 ; see 2 T. Kheel, Labor Law § 7.04[3][e] (1984).
The court's requirement that the reinstatement offers be held open for four years is vulnerable to similar attack. The court simply had no justifiable ba