The secretary shall enforce this act. The secretary shall make and, from time to time, revise regulations, with the assistance of the board, when requested by the secretary, which shall be deemed appropriate to carry out the purposes of this act and to safeguard the minimum wage rates thereby established. Such regulations may include, but are not limited to, regulations defining and governing bona fide executive, administrative, or professional employes and outside salespersons, learners and apprentices, their number, proportion, length of learning period, and other working conditions; handicapped workers; part-time pay; overtime standards; bonuses; allowances for board, lodging, apparel, or other facilities or services customarily furnished by employers to employes; allowances for gratuities; or allowances for such other special conditions or circumstances which may be incidental to a particular employer-employe relationship.