From the IBT Constitution:
Area, Multi-Area, Multi-Employer, National,
Company-wide or Industry-wide Contracts
Section 2(a). If a majority of the affiliated Local
Unions vote to participate in area, multi-area, national,
multi-employer, company-wide, or industry-wide negotiations
for an area, multi-area, national, multi-employer,
company-wide, or industry-wide agreement (hereinafter
“master agreement”), all involved affiliated Local
Unions shall comprise a multi-union unit, be bound by
such vote, must participate in such master agreement
bargaining and shall be bound by the agreement
approved as provided below. Upon completion of negotiations
by any committee designated as hereinafter set
forth to engage in negotiations of a master agreement,
such agreement shall be submitted to the membership
involved in such negotiations for their approval or rejection
as the final offer in accordance with Section 2(d)
herein.
Last sentence.