29 C.F.R. § 541.704
The use of manuals, guidelines or other established procedures containing or relating to highly technical, scientific, legal, financial or other similarly complex matters that can be understood or interpreted only by those with advanced or specialized knowledge or skills does not preclude exemption under section 13(a)(1) of the Act or the regulations in this part. Such manuals and procedures provide guidance in addressing difficult or novel circumstances and thus use of such reference material would not affect an employee's exempt status. The section 13(a)(1) exemptions are not available, however, for employees who simply apply well-established techniques or procedures described in manuals or other sources within closely prescribed limits to determine the correct response to an inquiry or set of circumstances.
29 C.F.R. §541.704