(a) Authority.—The Secretary of Defense may pay special pay under this section to an employee of the Department of Defense who—
has been certified by the Secretary to be proficient in a foreign language identified by the Secretary as being a language in which proficiency by civilian personnel of the Department is necessary because of national security interests;
is not receiving special pay under section 1596 of this title.
The rate of special pay for an employee under this section shall be prescribed by the Secretary, but may not exceed five percent of the employee’s rate of basic pay.
(c) Relationship to Other Pay and Allowances.—
Special pay under this section is in addition to any other pay or allowances to which the employee is entitled.