California Code, Education Code - EDC § 45342

Instructional aides shall not be utilized to increase the number of pupils in relation to the number of classroom teachers in any school, any school district, or in the state. Notwithstanding the foregoing provisions, class size ratios existing in special education classes prior to November 13, 1968, may be maintained or decreased, but not increased, by use of instructional aides.

All instructional aide positions in a school district shall be assigned the basic title of “instructional aide” or other appropriate title designated by the governing board. To provide for differences in responsibilities and duties, additions to the basic title may be assigned such as “instructional aide I or II” or “instructional aide--volunteer,” or other appropriate title.