system: You are a contract-analysis assistant performing a span-extraction task. You are given an excerpt from a commercial contract and the name of a clause type to locate within it.

Return the exact text of the requested clause, copied verbatim from the excerpt — identical wording and punctuation, with no paraphrasing, summarising, explanation, or added commentary.

The excerpt is one window of a much longer contract and often will not contain the requested clause. If the requested clause does not appear in this excerpt, respond with exactly: Not found.

Output only the extracted clause text, or the exact string `Not found.` — nothing else.

user: Contract excerpt:
"""
than the applicable Quarterly Volume Commitment for that Product then, in addition to paying any amounts incurred by Shipper pursuant to Section 3.4 with respect to Shipper Deliveries for such Quarter, Shipper shall also pay MPL a deficiency payment (the "Quarterly Deficiency Payment"); equal to the product of: (a) the difference between the applicable Quarterly Volume Commitment for that Product for such Quarter and the volume of Shipper Deliveries of that Product on the Pipeline for such Quarter (the "Deficiency Volume"); and (b) the applicable Tariff Rate for that Product for such Quarter. Each Product to which the Shipper is obligated to move as part of its committed volumes will be added together for one total Quarterly Deficiency Payment. Shipper's transportation of commodities outside this Agreement's definition of Product will not satisfy the obligation to move committed Product volume. All Product barrels moved by Shipper in excess of its Quarterly Volume Commitment will be attributed to Shipper's movements on the Pipeline as a Regular Shipper, subject to the applicable Rules & Regulations of the Tariff. 3.6 The dollar amount of any Quarterly Deficiency Payment paid by Shipper shall constitute prepayment for transportation of Product by Shipper on the Pipeline and will posted as a credit ("Prepaid Transportation Credits") to Shipper's account for that type of Product. If, during any Quarter of the Contract Year, Shipper deliveries on the Pipeline exceed the applicable Quarterly Volume Commitment requirements, Shipper shall be permitted to apply Prepaid Transportation Credits against any amount due from Shipper and payable to MPL with respect to the transportation of volumes on the Pipeline for such Quarter. Any Prepaid Transportation Credits that are not used by Shipper during the four (4) Quarters immediately following the Quarter for which said Prepaid Transportation Credits were posted to Shipper's account (the "Credit Period") will expire. Those Prepaid Transportation Credits that are in payment dispute in accordance with Section 3.4, shall be posted as a credit on the date the payment dispute is resolved. If during any such four (4) Quarter period the nominated volume on the Pipeline for any month equals or exceeds the applicable portion in the Quarterly Volume Commitment for the Pipeline for such month (the "Monthly Commitment"), but Shipper is prevented from shipping volumes in excess of the Monthly Commitment because of lack of available capacity, either because (a) the Pipeline is in allocation and Shipper is specifically subject to allocation per Exhibit C, (b) the Pipeline is undergoing testing, maintenance or repair, or (c) a Force Majeure has occurred that prevents MPL from transporting Shipper volumes on the Pipeline in excess of the Monthly Commitment, then the Credit Period shall be extended by an equivalent time period for which Shipper has been prevented from shipping volumes in excess of the Monthly Commitment. For the purposes of this Section 3.6, during the Term, if the Pipeline is in allocation for any portion of the month, the Pipeline will be considered to be in allocation for the entirety of such month. 3.7 Notwithstanding anything in Section 3.5 to the contrary, upon the expiration or termination of this Agreement for any reason to the extent that Shipper, at the time of such expiration or termination, holds any unused Prepaid Transportation Credits, Shipper shall be permitted to apply such Prepaid Transportation Credits against any amounts incurred by Shipper and 6 payable to MPL with respect to any Shipper deliveries on the Pipeline until the expiration of the applicable Credit Period with respect to such Prepaid Transportation Credits. This Section 3.7 shall survive the expiration or termination of this Agreement. 3.8 Shipper may not apply Prepaid Transportation Credits on differing types of Products; i.e, a Shipper may not use Prepaid Transportation Credits received for butane service on condensate, natural gasoline, or diluent service, or vice versa. Condensate, natural gasoline, and diluent are interchangeable from a volume commitment standpoint and shipping a total volume of any one or combination of these Products will be applied towards the Quarterly Volume Commitment. Should MPL proceed with butane service, Shipper will also have the opportunity to fulfill its Quarterly Volume Commitment on a calendar quarter basis for butane service, separate from condensate, natural gasoline, and diluent service. 3.9 If, following the binding open season and prior to the in-service date of the Tariff, MPL determines that it has available capacity not subscribed to during the binding open season, not to exceed 90% of Project Capacity ("Unsubscribed Capacity"), to the extent permitted by Governmental Authority; MPL will provide
"""

Extract the exact clause related to "Parties" from the excerpt above.

assistant: Shipper