"Enterer" includes any person who is the importer of record (under federal customs law) with respect to diesel fuel. If the importer of record is acting as an agent, the person for whom the agent is acting is the enterer. If there is no importer of record of diesel fuel entered into this state, the owner of the diesel fuel at the time it is brought into this state is the enterer.
Ca. Rev. and Tax. Code § 60013