Fundamentally, none of the agreements used in exploration and production are useful unless the ownership of the underlying oil and gas properties can be established to a reasonable certainty. In the domestic industry, historically, ownership has been established through the use of title opinions. The title opinions, whether acquisition, drilling, shut-in royalty, supplemental, division order, unit or financing opinions are among the more critical documents used to determine ownership of oil, gas and other minerals, and, in the case of financing arrangements, to determine the priority of liens. Mr. Borrego has examined title and prepared opinions in Texas since the beginning of his career, and, in addition, has reviewed opinions prepared by others in conjunction with the acquisition and divestiture of properties and in financing arrangements.