opinion: BROWNING, Circuit Judge:
  The Trades Council and Jens Horst-rup, its secretary-treasurer, ask us to set aside an order of the National Labor Relations Board based upon a holding that they had violated section 8(b) (7) (A) of the Act, 29 U.S.C. § 158(b) (7) (A), by picketing R. A. Chambers & Associates of Eugene, Oregon. 165 N.L.R.B. No. 86. The Board cross-petitions for enforcement.
  Chambers is a general contractor in the construction industry. Subcontractors do approximately 60 per cent of Chambers’ work; about 40 per cent is done by his own employees. Chambers’ employees are carpenters and laborers who are members of locals of the Laborers’ Union and the Carpenters’ Union. At the time of the picketing, Chambers was a party to collective bargaining contracts with these unions.
  The Trades Council is an association of local building trade unions, including the Laborers’ Union and Carpenters’ Union. The Trades Council was not certified as the representative of Chambers’ employees — its membership does not include individual employees. The purpose of the picketing was to require Chambers to execute a formal agreement with the Trades Council, the provisions of which are considered below.
  The Board concluded that the picketing violated section 8(b) (7) (A) because it had as an object requiring Chambers to recognize or bargain with the Trades Council as the representative of Chambers’ employees, at a time when Chambers had lawfully recognized other unions and a question of representation could not appropriately be raised under section 9(c) of the Act, 29 U.S.C. § 159(c).
  Except as we will note, the issues and arguments presented to us were considered by the Court of Appeals for the District of Columbia Circuit in Dallas Building & Construction Trades Council v. NLRB, 130 U.S.App.D.C. 28, 396 F.2d 677 (1968). That court enforced the Board’s order. We agree with the Dallas opinion, and enforce a similar order of the Board here.
  It would serve no useful purpose to deal again with the contentions disposed of in Dallas. With one preliminary observation, we confine our comments to matters not considered in that opinion.
  It must be conceded that the primary purpose of section 8(b) (7) (A) is to protect employees’ freedom of choice in selecting their bargaining agent from the coercive effect of picketing by a “stranger” union; and that it is not readily apparent that this purpose is served by applying the statute to picketing by an allied or affiliated labor organization rather than one hostile to the lawfully recognized union.
  However, Congress did not choose to rest the applicability of section 8(b) (7) (A) upon such a distinction. On the contrary, if the other conditions specified in the section are present, picketing is barred when the employer has lawfully rocognized “any other labor organization.” It cannot be supposed that Congress was unaware of the special problems in the construction industry (see, e. g., section 8(e)); and, as Dallas points out, Congress may well have intended to protect the employer from pressure even from allied or affiliated unions with regard to matters properly subject to settlement by agreement between the employer and the exclusive bargaining agent of his employes. 396 F.2d at 680-681.
  The exact language of section 8(b) (7) (A) is the product of intense legislative conflict and compromise (NLRB v. Suffolk County District Council of Carpenters, 387 F.2d. 170, 174 (2d Cir. 1967)); and, to an unusual degree, the words of the statute provide the only safe measure of the actual agreement between contending purposes and points of view. Cf. A. Cox, The Landrum-Griffin Amendments to the National Labor Relations Act, 44 Minn.L.Rev. 257, 266 (1959). Nonetheless, we agree, of course, that it would be proper to read a condition into the statutory language if the legislative history affirmatively supported the Trades Council’s thesis that Congress did not intend to bar picketing by an allied or affiliated labor organization in the construction industry. But it does not.
  The Board’s position, in this case and in Dallas, is that “an object [of picketing] is forcing or requiring an employer to recognize or bargain with a labor organization as the representative of his employees,” if a purpose of the picketing is to establish a continuing contractual relationship with the employer with regard to matters which could substantially affect the working conditions of his employees, and which are the proper subject of bargaining by a lawfully recognized exclusive representative of those employees. See 396 F.2d at 680-81.
  The Board found that the Trades Council picketed to require Chambers to execute a formal contract to remain in force from year to year unless either party gave notice of termination 60 days prior to an anniversary date. The proposed contract was to replace a similar agreement executed by the parties nine or ten years earlier.
  The Board further found that several of the provisions of the proposed contract related to subjects already covered by the collective bargaining agreements between Chambers and locals of the Laborers’ and the Carpenters’ Unions, and would have modified the terms of the latter agreements.
  Certain of these proposed provisions would have imposed greater restrictions upon the subcontracting of work by Chambers than were imposed by Chambers’ existing collective bargaining agreements with the locals. For the reasons stated in Dallas, picketing to secure a continuing agreement with respect to this subject matter intruded upon the area reserved to collective bargaining between Chambers and the craft unions representing Chambers’ employees.
  The Examiner held, and the Board agreed, that several other proposed provisions not involved in Dallas, fell in the same category.
  The first of these was a provision that the Trades Council would not be bound by the no-strike and arbitration clauses in the agreements with the Laborers’ Union and the Carpenters’ Union. A second provision would have freed the Carpenters' and Laborers’ Unions of the obligation to furnish workmen imposed by hiring-hall provisions of their agreements with Chambers during the time of any violation by Chambers of the proposed agreement with the Trades Council. The Trades Council’s argument in support of these two provisions is premised upon the validity of the central provisions restricting subcontracting which these two provisions were designed principally to enforce. The argument falls with its premise.
  This is equally true of the Trades Council’s defense of a final provision to the effect that the craft unions could not modify, amend or alter the proposed agreement without the approval of the Trades Council. The Board interpreted this proposed provision as requiring prior agreement by the Trades Council to the negotiation by Chambers and the craft unions of any change in the terms and conditions of employment of Chambers’ employees. The Trades Council argues that this provision applied only to the modification of its proposed agreement. Assuming the latter interpretation to be correct, the provision would require prior Trades Council approval of any changes in the subcontracting articles which were the heart of the proposed agreement. Since, as we have held, restrictions on subcontracting are matters solely for negotiation between Chambers and the lawful representatives of his employees, any provision concerning modification of those restrictions would also be reserved for negotiation between those parties.
  We enforce the Board’s order.
  . The Trades Council challenges the Board’s finding that Chambers’ employees were union members at the time collective bargaining contracts were executed with the locals. Chambers testified under oath that they were; and the weight of his testimony was for the Board to determine. There was no evidence to the contrary.
  . Chambers also became a party to collective bargaining agreements with two other local unions affiliated with the Trades Council, the Iron Workers and the Cement Masons, hut it appears that Chambers did not employ men in either craft.
  . It should be noted, however, as the trial examiner observed, that “There is no indication in this record of the position of the four crafts concerning this tactic by Respondents.” 165 N.L.R.B. No. 86, at note 5.
  . It is at least clear from the legislative history that § 8(b) (7) (A) was intended to protect both parties to a lawful bargaining relationship — the employer as well as his employees. I Leg.His. of the LMRDA of 1959 781-782; 2 Leg.His. of the LMRDA 994, 1185, 1191, 1291, 1518, 1576, 1582, 1828, 1858.
  . The Building and Construction Trades Department, AFL-CIO, amicus curiae, points out that § 8(b) (7) bars picketing to require an employer to recognize or bargain with a labor organization “as the representative” of his employees, and argues that the section therefore applies only where the picketing union seeks recognition as the exclusive representative of the employees. This contention was rejected in Dallas on the ground that it “does not appear to be compatible with the clear purpose of Section 8(b) (7) to prevent any infringement of the recognized union’s representative status.” 396 F.2d at 680 n. 5. If the construction suggested by amicus were adopted, § 8(b) (7) would have little or no substance since any union, competing or allied, could avoid the statute merely by limiting its demands upon the employer to anything less than the full range of bargainable subjects.
  . This position was foreshadowed by the Board’s pre-Landrum-Griffin Act interpretation of § 8(b) (4) (C). See Industrial Chrome Plating Co., 121 N.L.R.B. 1298, 1300 (1958); Lewis Food Co., 115 N.L.R.B. 890, 892-93 (1956).
  . The Trades Council contends that Chambers was still bound by this earlier agreement with it when he executed collective bargaining agreements with the local craft unions, and thus the local craft unions were not “lawfully recognized” by Chambers as required by § 8(b) (7) (A). Since the local craft union contracts were executed over a year before the picketing occurred, the Trades Council is barred by § 10(b) of the Act from asserting that those unions were not “lawfully recognized.” Rowan Stone Construction, 153 N.L.R.B. 659 n. 3. Nor could the Council have brought a petition for an election. NLRB v. Local 3, I.B.E.W., 362 F.2d 232, 236 (2d Cir. 1966).
  The Trades Council’s contention that the craft collective bargaining agreements were pre-hire agreements within the meaning of § 8(f) and therefore not a bar to a petition under § 9(e), is sufficiently answered in Dallas, 396 F.2d at 679 n. 4, on undistinguishable facts.
  . We agree with the holding in Dallas that this construction of § 8(b) (7) (A) is consistent with the letter and spirit of the first proviso in § 8(e). 396 F.2d at 682.
instruction: What follows is an opinion from a United States Court of Appeals.
  Intervenors who participated as parties at the courts of appeals should be counted as either appellants or respondents when it can be determined whose position they supported. For example, if there were two plaintiffs who lost in district court, appealed, and were joined by four intervenors who also asked the court of appeals to reverse the district court, the number of appellants should be coded as six.
  When coding the detailed nature of participants, use your personal knowledge about the participants, if you are completely confident of the accuracy of your knowledge, even if the specific information is not in the opinion. For example, if "IBM" is listed as the appellant it could be classified as "clearly national or international in scope" even if the opinion did not indicate the scope of the business. 
  
  Your task concerns the first listed appellant. The nature of this litigant falls into the category "private organization or association", specifically "business, trade, professional, or union (BTPU)". Your task is to determine what subcategory of private association best describes this litigant.