The PCOR is near the bottom of the page under "Change in Ownership Forms". Download PDF BOE-502-A REV.A Preliminary Change of Ownership Report is a document that must accompany any document that changes ownership on real property. Fill Out the Preliminary Change of Ownership Report (PCOR). The PCOR is required when property changes hands, to update the tax records. Preliminary Change Of Ownership Report (Contra Costa County) Form. This is a California form and can be use in Contra Costa Local County. Please Download PDF BOE-58-H REV. Please note: completing this form alone will not transfer stock to the Food Bank; you must contact your broker to complete the transfer. Fill in the blank form formatted to comply with all recording and content requirements.