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 second 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.

Opinion:
INTERNATIONAL UNION OF OPERATING ENGINEERS, AFL-CIO, LOCAL NO. 670, and Charles Hill, Plaintiffs-Appellants, v. KERR-McGEE REFINING CORPORATION, Defendant-Appellee.
No. 78-1679.
United States Court of Appeals, Tenth Circuit.
Argued Jan. 24, 1980.
Decided March 24, 1980.
David W. Kisner, Oklahoma City, Okl., for plaintiffs-appellants.
Carolyn G. Hill, Oklahoma City, Okl. (Charles W. Ellis of Ellis, Frates & Shotts, and Curtis B. Hendricks, Oklahoma City, Okl., with her on the brief), for defendantappellee.
Before SETH, Chief Judge, and HOLLOWAY and McKAY, Circuit Judges.
SETH, Chief Judge.
This appeal was taken from an order vacating an arbitration award. The appellant had been discharged for excessive absenteeism and for making false statements to obtain sick leave. Arbitration was had following the filing of a grievance and suit was then brought by the appellants to enforce the award [29 U.S.C. § 185(a)]. The court held for the employer and this appeal followed.
Appellant Hill was an employee at Kerr-McGee. He was represented by appellant International Union of Operating Engineers, which had entered into a collective bargaining agreement with Kerr-McGee. The relevant provisions in the agreement relating to sick leave are as follows:
8.7 Sick leave benefits will be paid only for absences from work caused by illness or injury to an .eligible employee personally. To qualify for benefits under this plan the employee must, if requested, present satisfactory evidence showing that his absence is due to illness or injury within the meaning of this plan. If an employee is off work due to illness or injury for three (3) or more days, the Company may require written proof from a licensed practicing physician (M. D.) or a licensed practicing Doctor of Osteopathy.
8.10 The Company will handle any particular sick leave case on its own merits. Any abuse or misuse of benefits granted employees under this plan, or false statements made to obtain benefits hereunder, will be cause for discharge,
After noting a general rise in sick leave, and a pattern of sick leave taken by employees in conjunction with days off, the Company reminded employees of the sick leave provision and of discharge for false statements used to obtain sick leave. Appellant Hill thereafter was absent from work for a period of several days. Hill’s supervisor was presented with a “sick note” from a. doctor after a note from a chiropractor was rejected as unacceptable under the collective bargaining agreement. The statement from Dr. Ellis in the sick note stated: “strep throat — off work May 16-25.” As there was a discrepancy between days of work missed and days noted by the doctor, Hill’s supervisor contacted Dr. Ellis and it developed that a doctor had not seen Hill.
Hill was discharged shortly thereafter “for using false statements to obtain sick leave benefits, and a history of excessive absenteeism during your employment.” A grievance was filed by the Union challenging the discharge, and the matter went to arbitration.
The arbitrator ruled that Hill was improperly discharged and should be reinstated with back pay after a five-day suspension. He held in part:
Had the charges in this discharge been restricted solely to the events related to the May 16 through May 20 absences, the decision in this case would have been simpler, but the discharge letter specifically states two charges — “false statements to obtain sick leave benefits” and a “history of excessive absenteeism.” If the evidence supporting either of these charges is not sufficient, then the discharge was not for just cause.
. [T]he Company did not submit sufficient evidence to prove its charge of excessive absenteeism. For this reason, the discharge cannot be upheld.
The Grievant must share some blame for the events that grew out of the May 16-20 absences. The Grievant did not make the statement that resulted in payment of sick leave benefits, but the Grievant did obtain the statement. Why, however, did the Company make the payments on the strength of Dr. Ellis’ statement if the Grievant had told his supervisor it was Dr. Meinders he had visited? At any rate, it appears that the Grievant was not completely straightforward. Discipline was warranted. (Emphasis supplied.)
The employer in its counterclaim to vacate the award contended that the arbitrator went outside the express terms of the agreement in reaching his decision. The court agreed, finding that the decision was clearly erroneous in requiring proof of both excessive absenteeism and false statements. The court said in part:
The error in the arbitrator’s decision is his ruling that the proof of both charges must be sufficient or the company’s discharge of plaintiff would not be sustained. Such a ruling does not comport with the express language of the Agreement. As provided in the Agreement, making false statements to obtain sick leave benefits is cause for discharge. Regardless of the finding or evidence with respect to any other ground for dismissal against any employee, a finding of abuse or misuse of benefits, or false statements made to obtain benefits, is cause for discharge. The Court cannot agree with the arbitrator or find any support in the agreement that all charges levied against an employee must be proved in order to sustain the discharge. The Agreement does not so provide and this Court does not so hold.
Initially, appellants argue that the counterclaim to vacate was barred by the running of the three-month statute of limitations of the Federal Arbitration Act, 9 U.S.C. § 12, and that the court erred in applying the longer state statute of limitations, 12 O.S.A. §§ 95, 273. However, the statute of limitations to be applied to a suit such as this under section 301 of the Labor Management Relations Act is the state statute of limitations. Automobile Workers v. Hoosier Corp., 383 U.S. 696, 704-5, 86 S.Ct. 1107, 1113, 16 L.Ed.2d 192: “[T]he timeliness of a § 301 suit, such as the present one, is to be determined, as á matter of federal law, by reference to the appropriate state statute of limitations.”
The crucial issue in this case is whether the trial court’s finding of clear error by the arbitrator is based upon a correct interpretation of the arbitrator’s decision and of the agreement. Appellants argue that the decision is ambiguous and susceptible to different “logical inferences” other than that made by the court that a violation of section 8.10 of the agreement had been found. They urge that under Steelworkers v. Enterprise Corp., 363 U.S. 593, 598, 80 S.Ct. 1358, 1361, 4 L.Ed.2d 1424 “[a] mere ambiguity in the opinion accompanying an award, which permits the inference that the arbitrator may have exceeded his authority, is not a reason for refusing to enforce the award.”
It is apparent that “[t]he award may not be contrary to the express language of the agreement, and must have rational support.” Fabricut, Inc. v. Tulsa General Drivers, etc., 597 F.2d 227, 229 (10th Cir.). In Mistletoe Exp. Service v. Motor Expressmen’s Union, 566 F.2d 692 (10th Cir.), we held that an award cannot be upheld if it is contrary to the express language of the contract. We are not here considering the merits of the award nor did the trial court. Instead it must be determined whether the arbitrator departed from the provisions provided in the labor contract.
In the case before us it is clear that the arbitrator ignored the express terms of the agreement. The arbitrator found that the appellant had obtained a false statement; that he was not “completely straightforward”; and that “discipline was warranted.” Under these clear findings the trial court correctly concluded that the only inference to be made was that Hill’s action violated section 8.10 as an “abuse or misuse of benefits, or false statements.”
Thus once a violation of that section had been established, discharge of the appellant was expressly provided for by the agreement. The arbitrator then added an additional condition or requirement not in the contract — that the appellee also prove excessive absenteeism. As in the Mistletoe ease, the arbitrator here substituted his views for the express provisions of the contract, added a provision not in the agreement, not bargained for, and in doing so “violated the essence of the agreement.”
AFFIRMED.

Question: This question concerns the second listed appellant. The nature of this litigant falls into the category "private organization or association", specifically "business, trade, professional, or union (BTPU)". What subcategory of private association best describes this litigant?

Choices:
Business or trade association
utilities co-ops
Professional association - other than law or medicine
Legal professional association
Medical professional association
AFL-CIO union (private)
Other private union
Private Union - unable to determine whether in AFL-CIO
Public employee union- in AFL-CIO (include groups called professional organizations if their role includes bargaining over wages and work conditions)
Public Employee Union - not in AFL-CIO
Public Employee Union - unable to determine if in AFL-CIO
Union pension fund; other union funds (e.g., vacation funds)
Other
Unclear

Answer: 5