The investigation, inspection, and law enforcement functions to carry out the provisions of 8 U.S.C. 1188, 20 CFR part 655, subpart B, or the regulations in this part, as provided in the regulations in this part for enforcement by the WHD, pertain to the employment of any H-2A worker, any worker in corresponding employment, or any U.S. worker improperly rejected for employment or improperly laid off or displaced. Such enforcement includes the work contract provisions as defined in Sec. 501.3(a).