48 CFR 616.203-4: 616.203-4 Contract clauses.

Contracting officers at domestic contracting activities may use an economic price adjustment clause based on cost indexes of labor or material in accordance with the circumstances listed in FAR 16.203-4(d) and after obtaining the approval of the head of the contracting activity. Overseas posts may use the clause at 652.216-71, Price Adjustment, when procuring continuing services (e.g., guard, janitorial, building maintenance, and gardening). Posts shall obtain A/OPE approval for any price adjustment clause that differs from the clause at 652.216-71.