California Code, Government Code - GOV § 18903

(a) For each class there shall be maintained a general reemployment list consisting of the names of all persons who have occupied positions with probationary or permanent status in the class and who have been legally laid off or demoted in lieu of layoff.

(b) Within one year from the date of his or her resignation in good standing, or his or her voluntary demotion, the name of an employee who had probationary or permanent status may be placed on the general reemployment list with the consent of the appointing power and the department. The general reemployment list may also contain the names of persons placed thereon by the department in accordance with other provisions of this part.