The primary function of California notaries public is to administer oaths and verify signatures. Notaries can also verify the signature of one person on behalf of another (called a subscribing witness). Notaries can also certify copies, including copies of a power of attorney document. Notaries can issue confidential marriage licenses if they have applied for such authorization from the county clerk of the county having jurisdiction over the marriage license, and have completed the mandatory course of instruction. California notaries can only perform marriage ceremonies if they are also a priest, minister, rabbi or other person authorized to do so under Family Code sections 400 to 402.