Cal. Sts. & Hy. Code § 6611
The action may be brought also at any time following the expiration of 30 days after the service of personal demand for payment upon the owner of the premises. Such demand shall be served in the manner provided by law for the service of a summons in a civil action. If the action is brought costs for the service of the demand shall be allowed in an amount equivalent to the fees prescribed by law for the service of summons.
The demand shall be in substantially the following form:
"Demand for Payment of Street Improvement Bond
You are hereby notified that Bond No. ____ Series No. ____ for an improvement in the City (or County) of ____ is delinquent. Unless the amount of the unpaid principal on said bond together with interest and penalties is paid to the city (or county) treasurer on or before 30 days after the service on you of this demand, the date of such service being this ____ day of ____, 20__, the undersigned will institute suit to foreclose the lien of said bond in the manner prescribed by law."
Ca. Sts. and High. Code § 6611