Expenditures in excess of the maximum amounts set forth in N.C. Gen. Stat. § 138-5 and 138-6 for travel and subsistence may be reimbursed if the prior approval of the department head is obtained. The Director of the Budget shall establish and publish uniform standards and criteria under which actual expenses in excess of the travel and subsistence allowances and convention registration fees as prescribed in N.C. Gen. Stat. § 138-5 and 138-6 may be authorized by department heads for extraordinary charges for hotel, meals, and registration, whenever such charges are the result of required official business. (1961, c. 833, s. 6.1; 1965, c. 1089; 1969, c. 1153; 1971, c. 881, s. 3; 1973, c. 595, s. 2; 1979,  c. 838, s. 17.)