The application of the exemption provided by section 13(b)(16)
depends on the nature of the employee's work and not on the character of
the employer's business. An employee is not exempt in any workweek
unless his employment in that workweek meets all the requirements for
exemption. To determine whether an employee is exempt an examination
should be made of the duties which that employee performs. Some
employees of the employer may be exempt and others may not.