This appeal features an interlocutory injunction issued on the authority of section 10(l ) of the National Labor Relations Act (NLRA), barring a labor union's innovative practice of conducting "group shop-ins" at secondary businesses (retail liquor outlets) as an outgrowth of its grievance with a primary employer (a beer distributor).1 After carefully considering the parties' positions in light of the pertinent authorities, we affirm the district court's order in all respects.I. THE FACTS AND THE PROCEEDINGS BELOW

The facts are set out in the district court's opinion, see Pye v. Teamsters Local Union No. 122, 875 F. Supp. 921, 923-24 (D.Mass.1995), and it would serve no useful purpose to rehearse them here. We content ourselves with a decurtate summary, presented in a manner that recognizes the statutory edge enjoyed by petitioner-appellee, the Regional Director of the National Labor Relations Board (NLRB or Board), in connection with the resolution of disputed factual issues and the inferences that may be drawn therefrom.

In November of 1994, respondent-appellant Teamsters Local Union No. 122 (the Union), then embroiled in a labor dispute with August A. Busch & Co. of Massachusetts, Inc. (Busch), organized three group shopping trips. During each outing, Union members descended, in droves and in concert, upon a designated retail establishment and engaged in multiple rounds of penny-ante purchasing, buying small, inexpensive items such as packs of chewing gum or bags of potato chips and paying for them (more often than not) with bills of large denomination. The sequelae were predictable: overcrowded parking lots, congested aisles, long checkout lines, and an exodus of regular customers. Although some of the group shoppers adorned themselves with Union symbols, the record contains virtually no proof of objectively expressive activity. More particularly, we can find no evidence suggesting that the Union, through group shopping, made any discernible attempt to communicate a defined message to the public.2

The three shop-ins, each involving a different retailer engaged in commerce, occurred at different locations in Massachusetts. The first incident transpired on November 17, when a band of approximately 70 Union members invaded the premises of Kappy's Liquors. The group shopping (which respondent prefers to call "affinity group shopping" or "associational shopping") persisted for some 45 minutes. The record reflects that at least one customer, apparently discouraged by the crush of Union members, left without transacting any business. The second shop-in occurred on November 23 at Wollaston Wine. This event also lasted about 45 minutes. Approximately 125 Union members participated. The third incident took place on November 25 at the liquor department of Price Costco, a discount house. It involved 50 or so Union members. The record does not pinpoint its duration. All three episodes began late in the afternoon (a prime time in the package store trade), and the latter two incidents occurred on the days before and after the Thanksgiving holiday (days that customarily produce substantial sales for liquor retailers). The record reveals that on at least two of the occasions store managers complained to a Union official who was on the premises, deploring the disruptive effects of the practice on their business. On the third occasion, the store owner apparently took his concerns directly to Busch.

Busch displayed little affinity for the Union's newly contrived stratagem. It complained to the Regional Director who, in turn, initiated an administrative adjudicatory process to examine whether the group shopping constituted an unfair labor practice prohibited by NLRA Sec. 8(b)(4)(ii)(B), 29 U.S.C. Sec. 158(b)(4)(ii)(B) (1988). The Regional Director theorized that, because the Union's actual labor dispute was with the primary employer, Busch, section 8(b)(4)(ii)(B) expressly prohibited it from trying to impair the relationships of secondary businesses (the retail stores) with Busch. Resisting this line of reasoning and denying any wrongdoing, the Union asseverated that these shop-ins were efforts to publicize its grievance with Busch, and were thus beyond the statute's proscriptive reach. The Union also asseverated that, in the end, the group shopping actually benefitted the retailers by generating hundreds of dollars in sales.

The Regional Director refused to buy the Union's wares. On December 1, she invoked section 10(l ) and petitioned for temporary injunctive relief in the federal district court, asserting that she had reasonable cause to believe that the associational shopping amounted to an illegal secondary boycott because its real purpose was to force the retailers to cease purchasing beverages from Busch. The district court, perceiving no need for an evidentiary hearing,3 found for the Regional Director. See Pye, 875 F. Supp. at 925-28. In due course, the court entered a decree that constitutes the actual injunction. Its key provisions are set out in the margin.4 This appeal ensued.

The so-called labor injunction has been among the most controversial landmarks dotting the historical landscape of American labor law. See generally Felix Frankfurter & Nathan Greene, The Labor Injunction (1930); Clarence E. Bonnet, The Origin of the Labor Injunction, 5 S.Cal.L.Rev. 105 (1931); Eileen Silverstein, Collective Action, Property Rights, and Law Reform: The Story of the Labor Injunction, 11 Hofstra Lab.L.J. 97 (1993). The section 10(l ) injunction is a special species of the labor injunction,5 designed to halt, inter alia, secondary activity that the Regional Director believes is in violation of NLRA Sec. 8(b)(4)(ii)(B) until the NLRB can consider the charges and reach a decision on the merits. The special nature of the section 10(l ) injunction informs our analysis of the case.

A. Standards of Review.

The standards of review applicable to appeals from district court decisions arising under section 10(l ), whether granting or denying the requested relief, are extremely deferential. We review the lower court's factual findings for clear error; we review its rulings of law de novo; and we review its ultimate conclusion, authorizing or withholding the requested relief, for abuse of discretion. See Hoeber v. Local 30, United Slate, Tile & Composition Roofers, Etc., 939 F.2d 118, 123 (3d Cir.1991); Union de Tronquistas de P.R., Local 901 v. Arlook, 586 F.2d 872, 876 (1st Cir.1978); see also Asseo v. Centro Medico Del Turabo, Inc., 900 F.2d 445, 450 (1st Cir.1990) (explicating identical standards under a corollary relief provision, NLRA Sec. 10(j), 29 U.S.C. Sec. 160(j)); Asseo v. Pan Am. Grain Co., 805 F.2d 23, 25 (1st Cir.1986) (same); see generally George Schatzki, Some Observations About the Standards Applied to Labor Injunction Litigation Under Sections 10(j) and 10(l) of the National Labor Relations Act, 59 Ind.L.J. 565, 575-76 (1983) (noting these standards of review and the striking pattern of appellate deference under section 10(l )).

Our level of deference is heightened because we are perched on the second tier of review vis-a-vis the Regional Director's assertion of reasonable cause. The district court occupies the first tier, and just as that court must itself defer in significant measure to the evaluative judgments of the Regional Director, see, e.g., Union de Tronquistas, 586 F.2d at 876, so, too, must we defer to the district court.6 Thus, in this doubly sheltered enclave, the judicial task is generally confined to weeding out wholly arbitrary or thoroughly insupportable petitions for relief. See Squillacote v. Graphic Arts Int'l Union, 540 F.2d 853, 859 (7th Cir.1976).

Of course, an important reason undergirding the deferential standard of judicial review in section 10(l ) cases is that neither the district court nor the court of appeals is adjudicating the merits, as such, to determine whether an unfair labor practice occurred. To the contrary, the courts' role at this stage is merely to supply a stopgap, that is, to palliate a likely violation detected by the Regional Director "pending the final adjudication of the Board with respect to such matter." 29 U.S.C. Sec. 160(l ). Consequently, a decision in a section 10(l ) proceeding is circumscribed in both time and scope, and any relief that may be granted is effective only while the related unfair labor practice charge is pending before the NLRB.7 See Sears, Roebuck & Co. v. Carpet, Linoleum, Soft Tile & Resilient Floor Covering Layers, 397 U.S. 655, 658-59, 90 S. Ct. 1299, 1301-02, 25 L. Ed. 2d 637 (1970) (per curiam); Walsh v. International Longshoremen's Ass'n, 630 F.2d 864, 868 (1st Cir.1980). Given the design of the statute, the agency expertise involved, and the two-tiered structure of review, a party appealing from an order granting or refusing a temporary injunction pursuant to section 10(l ) confronts the sobering prospect that most battles over the appropriateness of such redress will be won or lost long before appellate review takes hold.

B. Standard of Analysis.

Congruent with these deferential standards of review, the analytic path to be traversed in a section 10(l ) case is narrower than that typically travelled in the course of reviewing the grant or denial of preliminary injunctive relief. Indeed, "in a section 10(l ) case the judicial inquiry is only, or at least primarily, whether there is reasonable cause to believe a section 10(l ) offense has been committed." Maram v. Universidad Interamericana de P.R., Inc., 722 F.2d 953, 958 (1st Cir.1983). Other factors that ordinarily inform district court actions in respect to temporary injunctions are, at most, of secondary interest. See id. (concluding that "the special importance that Congress attaches to section 10(l ) offenses indicates ... a strong presumption of irreparable harm, with the balance in favor of the charging party, and that the public interest favors the injunction"). Hence, the method of analysis that governs appellate review of the propriety and scope of a section 10(l ) injunction is best described as follows:

First, the court must determine whether the Regional Director has reasonable cause to believe that the elements of an unfair labor practice are present. In this regard, the Director need only show the existence of credible evidence, even if disputed, together with reasonable inferences, which support [her] conclusions.... Second, the court must conclude that the legal theories relied upon by the Director are not without substance. Finally, it must find that temporary injunctive relief is "just and proper" in terms of effectuating the purposes of the Act.

Union de Tronquistas, 586 F.2d at 876 (citations omitted).

Having stated the bareboned test, we next flesh out its three constituent parts.

1. Reasonable Cause. The centerpiece of the required analysis is the supportability vel non of the Regional Director's determination that there is reasonable cause to believe that an unfair labor practice has been, or is being, committed. The case law reveals two principles, in particular, that demarcate the meaning and the margins of this requirement.

First, the Regional Director's evidentiary burden, whether measured quantitatively or qualitatively, is modest. Although courts phrase this principle in different ways, sometimes speaking in terms of the Regional Director's burden of proof, see, e.g., Hirsch v. Building & Constr. Trades Council, 530 F.2d 298, 302 (3d Cir.1976) (characterizing burden as "relatively insubstantial"), sometimes speaking in terms of the quantum of proof, see, e.g., Gottfried v. Sheet Metal Workers' Int'l Ass'n, Etc., 927 F.2d 926, 927 (6th Cir.1991) (requiring only that the Regional Director bring forth "some evidence" in support of her petition), and sometimes speaking in terms of the probative value of evidence as opposed to its raw quantity, see, e.g., Union de Tronquistas, 586 F.2d at 876 (requiring that the Regional Director "show the existence of credible evidence, ... together with reasonable inferences," to support her conclusions), the thrust of the decided cases is uniform: the Regional Director need not prove that the respondent has in fact violated the NLRA, but, rather, she need only make a minimal evidentiary showing of good reason to believe that the essential elements of an unfair labor practice are in view.

The second principle that is germane to the reasonable cause inquiry is that genuinely disputed issues of material fact should be resolved at this early stage in favor of the Regional Director's exposition. See Maram, 722 F.2d at 958; Union de Tronquistas, 586 F.2d at 876; Kaynard v. Mego Corp., 633 F.2d 1026, 1031 (2d Cir.1980). Put another way, in proceedings under section 10(l ) the Regional Director must be given the benefit of every legitimate fact-based doubt. Thus, a reviewing court "need not concern itself with resolving conflicting evidence if facts exist which could support the [Regional Director's] theory of liability." Fleischut v. Nixon Detroit Diesel, Inc., 859 F.2d 26, 29 (6th Cir.1988).

2. Legal Theory. The next segment of the tripartite analysis implicates the legal theory on which the Regional Director relies. The requirement is straightforward: the Regional Director's theory need not be irreproachable; it suffices if it "is not without merit." Union de Tronquistas, 586 F.2d at 877. In other words, the Regional Director need not persuade the court then and there of her theory's ultimate validity, but she must show that the theory is presentable. See Hirsch, 530 F.2d at 302 (explaining that the legal theory upon which the Regional Director proceeds must be "substantial and not frivolous"); see also Hoeber, 939 F.2d at 123-24 (quoting Hirsch with approval); see generally 8 Theodore Kheel, Labor Law Sec. 38.01, at 38-9 (1995).

3. Just and Proper. Finally, injunctive relief granted pursuant to section 10(l ) must, by the terms of the statute itself, be "just and proper." Both the purpose and the contours of this imperative are relatively well-developed. "The purpose of the Sec. 10(l ) injunction is to preserve the status quo in order that the ultimate decision of the Board would not be negated or rendered moot by intervening events." Compton v. National Maritime Union of Am., 533 F.2d 1270, 1276 (1st Cir.1976). Thus, temporary injunctive relief, if otherwise warranted, passes the "just and proper" test as long as it comprises a reasonable means of ensuring the efficacy of the Board's final order, or preserving the status quo, or permitting administrative proceedings to go forward without undue hindrance, or preventing unjustified interruption of the free flow of commerce, or forestalling the repetition of unfair labor practices. See, e.g., Hoeber, 939 F.2d at 122; Gottfried, 927 F.2d at 927; Asseo, 900 F.2d at 455; Union de Tronquistas, 586 F.2d at 878. In this sense, the purpose of the section 10(l ) injunction is simply a narrower, more specific expression of the purpose underlying preliminary injunctions in general. See, e.g., CMM Cable Rep., Inc. v. Ocean Coast Props., Inc., 48 F.3d 618, 620 (1st Cir.1995) ("The purpose of a preliminary injunction is to preserve the status quo, freezing an existing situation so as to permit the [ultimate trier of the issues], upon full adjudication of the case's merits, more effectively to remedy discerned wrongs.").

Since a section 10(l ) injunction "may enjoin only those unlawful labor practices specified in the [NLRA]," Hendrix v. International Union of Operating Eng'rs, Local 571, 592 F.2d 437, 445 (8th Cir.1979), the form of the injunction must dovetail with the statutory goals. However, less is often better than more, and the relief granted should be narrowly tailored to that which is reasonably necessary to stop mischief, prevent additional harm, and ensure effective final relief. See Gottfried, 927 F.2d at 928; Potter v. Houston Gulf Coast Bldg. Trades Council, 482 F.2d 837, 841 (5th Cir.1973).

C. Applying the Standards.

Applying these standards of review and analysis, we conclude that the instant decree passes muster.

1. Reasonable Cause. The statutory proscription that triggered section 10(l ) in this case, namely, section 8(b)(4)(ii)(B), makes it "an unfair labor practice for a labor organization or its agents ... to threaten, coerce, or restrain any person engaged in commerce or in an industry affecting commerce, where ... an object thereof is ... forcing or requiring any person ... to cease doing business with any other person...." The question at this step of the analysis, therefore, reduces to the supportability of the district court's finding that the Regional Director had reasonable cause to believe (1) that the activity of group shopping might somehow threaten, coerce, or restrain a retail liquor outlet, and (2) that an object of the group shopping was to force or require such secondary businesses to sever relations with Busch. We conclude that this finding is not clearly erroneous.

First and foremost, it is reasonable to regard the practice of group shopping as potentially coercive. The character of the conduct--including the use of all or virtually all of a store's parking lot, the occupation of much of the interior shopping area, the forbidding presence of a throng of people acting in unison, and the fostering of long checkout lines through repeated purchases of small items with large bills--tends by its very nature to disrupt normal commercial activity and, thus, to place economic pressure on a retail establishment to appease the Union by, say, cutting back on dealings with the primary employer.8 The Union counters that, even so, the evidence falls short. Insofar as this argument presumes that moderately obstructive conduct by a union is not alone sufficient either to trigger section 8(b)(4)(ii)(B) or to justify a section 10(l ) injunction, we accept the presumption. See National Maritime Union of Am. v. NLRB, 367 F.2d 171, 176 (8th Cir.1966), cert. denied, 386 U.S. 959, 87 S. Ct. 1030, 18 L. Ed. 2d 108 (1967). Because section 8(b)(4) ultimately proscribes objects rather than merely the means adopted to accomplish them, the record must contain enough evidence to permit a finding that the Union actually possessed the statutorily proscribed object of forcing secondary establishments to cease doing business with the primary employer.

We think that the Regional Director satisfied this requirement here. To be sure, there is no smoking gun, no direct evidence of an avowed intention to influence the retailers' commercial behavior. But a "union's 'object' may be inferred from its acts," New York Mailers' Union No. 6 v. NLRB, 316 F.2d 371, 372 (D.C.Cir.1963), and particularized evidence of subjective intent is not essential for proof of a violation. See NLRB v. Erie Resistor Corp., 373 U.S. 221, 227, 83 S. Ct. 1139, 1144-45, 10 L. Ed. 2d 308 (1963); NLRB v. Denver Bldg. & Constr. Trades Council, 341 U.S. 675, 688-89, 71 S. Ct. 943, 951-52, 95 L. Ed. 1284 (1951); Soft Drink Workers Union Local 812 v. NLRB, 657 F.2d 1252, 1261-62 (D.C.Cir.1980); Pickens-Bond Constr. Co. v. United Bhd. of Carpenters & Joiners of Am., Local 690, 586 F.2d 1234, 1241 (8th Cir.1978); see also International Longshoremen's Ass'n v. Allied Int'l, Inc., 456 U.S. 212, 224, 102 S. Ct. 1656, 1663, 72 L. Ed. 2d 21 (1982) (confirming that a union "must take responsibility for the 'foreseeable consequences' of its conduct") (quoting NLRB v. Retail Store Employees Union, Local 1001, 447 U.S. 607, 614 n. 9, 100 S. Ct. 2372, 2377 n. 9, 65 L. Ed. 2d 377 (1980)). It follows that, if an unwholesome object can logically be inferred from the nature of the conduct, evaluated in light of the practical realities of a given situation, then direct evidence of the object need not be produced. See, e.g., Local 357, Int'l Bhd. of Teamsters, Etc. v. NLRB, 365 U.S. 667, 675, 81 S. Ct. 835, 839-40, 6 L. Ed. 2d 11 (1961).

Here, the facts permitted the Regional Director rationally to infer an unlawful object on the Union's part. The Union's conduct was undertaken in such a way, and at such times, as to maximize its obstructiveness. And, moreover, this effect can easily be viewed as primary and deliberate, not incidental and accidental. Hence, the Regional Director could reasonably have believed that the principal object of the shop-ins was to force the secondary businesses to stop trading with the primary employer. As the district court perspicaciously observed, the group shop-ins can reasonably be interpreted as having been designed to send a dual message to the retailers: first, "that the Union has the ability to interfere with the working of their business at any time," and second, that the retailers ought "not to get involved with Busch" in the ongoing labor dispute by picking up merchandise directly from Busch's warehouse. Pye, 875 F. Supp. at 926.

The Union has a fallback position. Citing both Edward J. DeBartolo Corp. v. Florida Gulf Coast Bldg. & Constr. Trades Council, 485 U.S. 568, 108 S. Ct. 1392, 99 L. Ed. 2d 645 (1988), and the First Amendment, the Union hawks its right, specifically preserved by section 8(b)(4), to publicize its grievance with a primary employer.9 Building on this theme, the Union claims that the injunction is tantamount to an impermissible content-based regulation because it prevents activities that could affect the public's marketplace decisions about what beer to purchase. While the Union's theory might raise potentially interesting issues if anchored in the record, see generally Lee Goldman, The First Amendment and Nonpicketing Labor Publicity Under Section 8(b)(4)(ii)(B) of the National Labor Relations Act, 36 Vand.L.Rev. 1469 (1983), it floats free of factual support and, therefore, need not concern us.

In the first place, we--like the district court, see Pye, 875 F.Supp. at 927--remain unconvinced that the Union's affinity group shopping, under the circumstances recounted in the record, can be deemed objectively expressive. At any rate, there is little or no evidence to suggest that the Union's object in mounting group shop-ins was related to publicity in any meaningful sense, or that the participating Union members were actually engaged in expressive activity. In turn, because the group shopping was not a publicity-based appeal to consumers, the principal cases cited by the Union which address the constitutional and statutory status of such activity, DeBartolo included, are simply not relevant to the disposition of this case.

In the second place, section 8(b)(4)(ii)(B) is in play as long as forcing one person to stop doing business with another is an object of the allegedly unlawful activity; the statute requires neither that the proscribed object be the exclusive object nor even the primary object. See Denver Bldg. & Constr. Trades, 341 U.S. at 689, 71 S.Ct. at 951-52; Local Union No. 25 v. NLRB, 831 F.2d 1149, 1153 (1st Cir.1987); Carpet, Linoleum, Soft Tile & Resilient Floor Covering Layers v. NLRB, 467 F.2d 392, 399 n. 13 (D.C.Cir.1972). Thus, whatever mixed motives the Union harbored are of considerably less import once an unlawful object is discerned.10 This is especially true in the precincts patrolled by section 10(l ). Even if "[t]he claims of the Union based on the first amendment to the Constitution and on the 'publicity proviso' ... are not insubstantial," Solien v. United Steelworkers of Am., 593 F.2d 82, 88 n. 3 (8th Cir.), cert. denied, 444 U.S. 828, 100 S. Ct. 54, 62 L. Ed. 2d 36 (1979), it is not for this court to pass upon them during the quintessentially preliminary inquiry that section 10(l ) entails. Rather, "[t]he Board should consider the claims in question, and its determinations with respect to them will be subject to review here if any direct proceeding is commenced in this court...." Id.

To sum up, it is not the responsibility of the courts to override the Regional Director's interpretation of the facts when that interpretation is rationally supported by the record. Applying this generous standard, we approve the lower court's holding that the Regional Director had reasonable cause to believe that the Union's practice of group shopping was in potential violation of section 8(b)(4)(ii)(B).

2. Legal Theory. We turn next to the question of whether the instant case fits within the legal contours of section 8(b)(4)(ii)(B). Having mulled the Regional Director's theory--that the Union's group shopping amounted to an unlawfully coercive secondary boycott--we conclude that it is sufficiently colorable.

The legal significance of the practice of group shopping is a matter of first impression. But, the novelty of a Regional Director's legal theory should rarely, in and of itself, foreclose the availability of injunctive relief under section 10(l ). Novelty does not necessarily signify insubstantiality. See, e.g., Hendrix, 592 F.2d at 442-43; Squillacote, 540 F.2d at 858; Boire v. International Bhd. of Teamsters, Etc., 479 F.2d 778, 790 (5th Cir.1973); cf. EEOC v. Steamship Clerks Union, Local 1066, 48 F.3d 594, 607 n. 13 (1st Cir.1995) ("It would be a peculiar rule of construction if a statute could not be applied in a certain manner unless it had already been applied in that manner in a previous case."), petition for cert. filed, 63 U.S.L.W. 3874 (U.S. May 26, 1995) (No. 94-1953). Thus, we hold that a novel legal theory may, if plausible, provide an appropriate foundation for a section 10(l ) injunction.

We have little difficulty in finding that the Union's group shopping plausibly could be deemed a coercion-based secondary boycott under section 8(b)(4)(ii)(B) and, hence, that there is adequate legal substance behind the issuance of the injunction. The language of section 8(b)(4)(ii) "is pragmatic in its application, looking to the coercive nature of the conduct, not to the label which it bears." Local Union No. 25, 831 F.2d at 1153 (citation and internal quotation marks omitted). Although group shopping, as conducted by the Union in this case, is a new twist and may not fit the traditional conception of a secondary boycott, see, e.g., Denver Bldg. & Constr. Trades, 341 U.S. at 687, 71 S.Ct. at 950-51 (describing a classic secondary boycott), this qualification mostly serves to earn the Union high marks for ingenuity. Coercion under section 8(b)(4)(ii)(B) is a broad concept, and the NLRB has not hesitated to include varied forms of economic pressure within the conceptual ambit. See, e.g., International Union, United Mine Workers of Am., 304 N.L.R.B. 71, 72-73, 1991 WL 163077 (1991) (finding unlawful coercion where union members caused a disturbance at a motel housing striker replacements, reasoning that the motel was a neutral employer and the union activity could pressure it to terminate its relationship with the labor supply contractor in order to force the latter to cease doing business with the primary employer), enforced, 977 F.2d 1470 (D.C.Cir.1992); Local No. 742, United Bhd. of Carpenters & Joiners of Am., 237 N.L.R.B. 564, 565-66, 1978 WL 8384 (1978) (finding that a union's quid pro quo request for premium pay from a neutral employer was unlawfully coercive because it was actually an effort to cause the modification of that employer's relationship with another employer); Service & Maintenance Employees Union, Local 399, 136 N.L.R.B. 431, 436-37 (1962) (holding that a union's generally nonexpressive marching around the main entrance of a sports arena, impeding public access, constituted unlawful coercion). Here, though one can imagine more significant forms of economic pressure than associational shopping, we nonetheless believe that the Regional Director's legal theory is sufficiently substantial that the district court's approbatory conclusion must be left intact.11

3. Just and Proper. We come finally to the question of whether the injunctive relief structured below can be deemed just and proper in light of the relevant factual and legal circumstances. We conclude that it can.

The district court held that injunctive relief is just and proper in this case because of its relationship to two statutory goals: (1) to prevent disruptions in the flow of commerce, and (2) to protect innocent third parties from becoming embroiled in a labor dispute. See Pye, 875 F. Supp. at 928. This threshold determination rests on empirical and legal bedrock. It is indisputable that the statutory proscription of secondary boycotts contemplates both the maintenance of an unhindered stream of commerce, see, e.g., Hoeber, 939 F.2d at 122; Union de Tronquistas, 586 F.2d at 878, and the shielding of secondary businesses from unlawful intrusions, see, e.g., International Longshoremen's Ass'n, 456 U.S. at 223 n. 20, 102 S. Ct. at 1663 n. 20; Denver Bldg. & Constr. Trades, 341 U.S. at 692, 71 S.Ct. at 953. After all, "[a] union has a right to press a recalcitrant employer within the limits of the law; but, [a secondary business] has an equal and correlative right to be protected from becoming a union pawn in an end game directed at some other employer." Local Union No. 25, 831 F.2d at 1152. On this basis, then, temporary injunctive relief of some sort is clearly just and proper.

Starting from this major premise, our focus necessarily becomes the scope of the decree that the lower court actually entered. The Union tells us that the decree is vague and overbroad. We reject this characterization. The injunction's prohibitory ambit is quite clear and its contours are rather specific. Short of cataloguing each and every potential violation, we do not see what further particularization the district court could reasonably have inserted. The requirement that temporary injunctions be clear and specific, Fed.R.Civ.P. 65(d), does not mean that they must read like the working plans for building hydrogen bombs. See Pacific Maritime Ass'n v. International Longshoremen's & Warehousemen's Union, 517 F.2d 1158, 1162-63 (9th Cir.1975).

We likewise fail to discern any merit in the Union's allegation of overbreadth. The injunction carefully proscribes certain types of activity, aimed at secondary businesses, undertaken by the Union and other denominated individuals, with a specific (unlawful) intent. No more is exigible.

The Union's last-ditch argument is that the injunction should be expressly limited in duration, particularly since it will remain operative until the Board acts, and that agency may not reach a decision on the merits for some time. In support of this argument, the Union cites Eisenberg v. Hartz Mountain Corp., 519 F.2d 138 (3d Cir.1975), in which the court held that section 10(j) injunctions, absent extraordinary circumstances, should be confined to six months in duration. See id. at 144. The Union's reliance on Eisenberg is unavailing. For one thing, that case involves section 10(j), not section 10(l ), and the differences between the two provisions are not insignificant. See supra note 7 (contrasting the two provisions); see also Maram, 722 F.2d at 957-58 (explaining why the range of considerations affecting the propriety of injunctive relief varies between sections 10(j) and 10(l )). For another thing, several other circuits have expressly declined to adopt the Third Circuit's inelastic six-month rule, instead leaving the matter of duration to be decided by individual district courts on a case-by-case basis. See, e.g., Sheeran v. American Commercial Lines, Inc., 683 F.2d 970, 980-81 (6th Cir.1982); Kaynard, 633 F.2d at 1035; Dawidoff v. Minneapolis Bldg. & Constr. Trades Council, 550 F.2d 407, 414 (8th Cir.1977); Squillacote, 540 F.2d at 860. Hendrix typifies the reasoning of those courts. There, the Eighth Circuit stated: "We find the congressional history indicates that Congress was aware of the lengthy Board hearing procedures when Section 10(l ) was enacted. Since Congress did not impose a time limit on a Section 10(l ) injunction, we find no reason why this Court should impose such a limit." Hendrix, 592 F.2d at 446.

A measure of adjudicatory delay is one of the crosses that contemporary litigants must bear. See, e.g., Maram, 722 F.2d at 960 ("A busy administrative agency cannot operate overnight. The very fact that it must exercise discretion, and that its decision is entitled to presumptive weight, indicate that it should have time to investigate and deliberate.") (footnote and citation omitted). Thus, we abjure the Third Circuit's rule and hold, instead, that the question of whether an injunction issued under section 10(l ) should be temporally limited--and, if so, to what extent--is a matter within the sound discretion of the district court.

We add an eschatocol of sorts. By declining the Union's invitation to sponsor a per se durational rule, we in no way intend to condone needless delay in the administrative adjudicatory process. We anticipate that the Board will proceed with dispatch to decide the merits of all section 10(l ) cases. If this prediction proves to be overly optimistic in a particular instance, the Union may, if it can make a credible showing that the Board's delay is genuinely undue, ask the district court to modify or dissolve the temporary injunction. See, e.g., Asseo, 805 F.2d at 29 (suggesting that the Regional Director's request for a temporary injunction should be taken as "a promise of a speedy [administrative] disposition, with the risk of dissolution, or modification, by the court, on motion ..., if the promise is not kept"); Solien, 593 F.2d at 88 (suggesting that if agency action is unreasonably delayed in a section 10(l ) case, a union may seek a modification or dissolution of the challenged injunction in the district court).

We need go no further. The temporary injunction, as granted, is grounded in the Regional Director's supportable finding of reasonable cause, rests on a credible legal theory, and is suitable in both its proscriptive reach and its temporal scope. Accordingly, we uphold it in all respects.

Affirmed.