4.15 Sick Leave Positions Upon the vacancy of any position covered by these rules, the Appointing Authority shall, if he/she assigns an employee in a classification of lower grade and pay to that vacancy for a period of more than 30 calendar days, request approval of the Personnel Administrator for the temporary appointment of the employee to the position. The employee so appointed shall be entitled to the compensation of the higher grade from the first day of assignment. This rule does not apply to assignment of an employee to cover a higher position when the incumbent of the higher position is absent on vacation leave but is intended to apply only when the incumbent of the higher position is on sick leave (M.G.L., Chapter 30, §24B).