The Act has applied since 1938 and continues to apply to all employees, not specifically exempted, who are engaged: (a) In interstate or foreign commerce or (b) in the production of goods for such commerce, which is defined to include any closely related process or occupation directly essential to such production. (See §§ 779.12-779.16 for definitions governing the scope of this coverage.) Prior to the 1961 amendments a retailer was not generally concerned with the coverage provisions as they applied to his individual employees because retail or service establishments ordinarily were exempt. However, in some cases such coverage was applicable as where employees were employed in central offices of warehouses of retail chain store systems and, therefore, were not exempt. (See § 779.118.) Some exemptions for retail or service establishments were narrowed as a result of the 1961 amendments and further revised or eliminated by the 1966 amendments effective February 1, 1967. Therefore, discussion of the individual coverage provisions of the Act is pertinent and this subpart will discuss briefly the principles of such coverage with particular reference to employment in the retail or service trades. A more comprehensive discussion with respect to employees engaged in commerce or in the production of goods for commerce may be found in part 776 of this chapter, the general coverage bulletin.