California Code, Government Code - GOV § 66434.2

(a) On or after January 1, 1987, a city or county may, by ordinance, require additional information to be filed or recorded simultaneously with a final or parcel map.  The additional information shall be in the form of a separate document or an additional map sheet which shall indicate its relationship to the final or parcel map, and shall contain a statement that the additional information is for informational purposes, describing conditions as of the date of filing, and is not intended to affect record title interest.  The document or additional map sheet may also contain a notation that the additional information is derived from public records or reports, and does not imply the correctness or sufficiency of those records or reports by the preparer of the document or additional map sheet.

(b) Additional survey and map information may include, but need not be limited to:  building setback lines, flood hazard zones, seismic lines and setbacks, geologic mapping, and archaeological sites.