Cal. Code Regs. tit. 2 § 549.12
The Department of General Services shall utilize the following certification process for all classes which would normally fall under the provisions of Government Code Sections 19057 and 19057.4 and are used within the department:
For positions in these classes, there shall be certified to the appointing power the names and addresses of all those eligibles whose scores, at time of certification, represent the three highest ranks on the employment list for the class, and who have indicated their willingness to accept appointment under the conditions of employment specified.
For purposes of ranking, scores of eligibles on employment lists for these classes shall be rounded to the nearest whole percent. A rank shall consist of one or more eligibles with the same whole percentage score.
If the names on the list from which certification is being made represent fewer than three ranks, then additional eligibles shall be certified from the various lists next lower in order of preference until names from three ranks appear. If there are fewer than three names available for certification, and the appointing authority does not choose to appoint from among these, the appointing authority may demand certification of three names. In that case, examinations shall be conducted until at least three names may be certified by the procedure described in this section; if the appointing authority is going to fill the position using the eligible list, it shall fill the position by appointment of one of the persons certified.
Cal. Code Regs. Tit. 2, § 549.12