Addendum for Reservation of Oil, Gas and Other Minerals. PARTIES: The parties to this contract are.(Seller) and. (Buyer). Utilize our Sales Agreement to document the sale of any item, ensuring protection for both the buyer and the seller. Order. This document contemplates that the buyer and the seller will negotiate and incorporate all of the terms and conditions of the transaction into this. The seller is a merchant in the business of manufacturing or selling durable goods of the type that are sold under the agreement. Seller warrants that the goods are free from any and all security interests, liens, and encumbrances. Use the full legal names of the buyer and seller.