Cal. Elec. Code § 9315
The persons filing an initiative petition pursuant to this article may file a written argument in favor of the ordinance. The district board may submit an argument against the ordinance. Neither argument shall exceed 300 words in length, and both arguments shall be printed and mailed to each voter with the voter information guide for the election.
The following statement shall be printed on the front cover, or if none, on the heading of the first page, of the printed arguments:
"Arguments in support of or in opposition to the proposed laws are the opinions of the authors."
Printed arguments submitted to voters in accordance with this section shall be titled either "Argument In Favor Of Measure ____" or "Argument Against Measure ____," accordingly, the blank spaces being filled in only with the letter or number, if any, designating the measure. At the discretion of the district elections official, the word "Proposition" may be substituted for the word "Measure" in the titles. Words used in the title shall not be counted when determining the length of any argument.
Ca. Elec. Code § 9315