Cal. Sts. & Hy. Code § 2950
If the legislative body finds, after taking the steps provided by Sections 2821, 2822 and 2823, that the probable assessments will not exceed the limitations set up by this division, it may cause the clerk to mail prepaid postcards giving notice of its findings and proposed action. Each such notice shall have attached thereto an addressed reply postcard with the return postage thereon guaranteed.
The cards shall be mailed to each person to whom land in the proposed assessment district is assessed on the last equalized county assessment roll available on the date the report is commenced, at his address as shown upon such roll and to any person whether owner in fee or having a lien upon or legal or equitable interest in any land within the proposed district who has filed with the clerk his name and address and the designation of the land in which he is interested.
Ca. Sts. and High. Code § 2950