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:
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hereof. f) Execute the bond in favor of ECOPETROL. g) Make the payment of the shipping tax under the conditions set out in this Contract and the law. h) Execute all other obligations derived from the nature of the Contract. a) In addition to the provisions in the Manual of the Shipper, ECOPETROL shall not be responsible for any faults in the Service, or the loses, damage or deterioration the Crude may suffer, if the fault in the Service, the loss, damage or deterioration of the Crude are due to (i) events of force majeure or acts of nature, (ii) Acts from third parties, (iii) vice inherent to the Crude, or (iv) fault attributable to the Sender (hereinafter, the "Excusable Events"). b) ECOPETROL shall only be responsible for the faults in the Service or loses, damage or deterioration the Crude may suffer to the extent it does not demonstrate that (i) no Excusable Event has occurred, and also, (ii) ECOPETROL failed to adopt the reasonable measures any shipper would have taken according to the requirements of operation of a pipeline with similar characteristics to the Pipeline, to avoid the damage or its aggravation. c) In all other events, different than those in connection with the provision of the Service, ECOPETROL shall be liable to the extent in incurs in gross negligence. d) Save the event of gross negligence or willful misconduct, pursuant to the provisions in this numeral 11.2, the responsibility of ECOPETROL under the Contract hereof under no circumstance shall exceed seventy five per cent (75%) of the value of the Crude lost or damaged by causes attributable to ECOPETROL. 6 11.3 Crude Assessment: In order to determine the value of the Crude for liability purposes based on the previous numeral, ECOPETROL shall establish the following rules: a) For those Pipelines using the mechanism of Volumetric Compensation for Quality and pursuant to the indications in the Manual of the Shipper, the value of the Crude shall be determined based on the result generated by the application of said mechanism defined for the Pipeline for the month in which the loss or damage of Crude occurs. b) For intermediate Pipelines and/or ending in Sea Terminals and not using the mechanism of Volumetric Compensation for Quality, the assessment of the Crude shall be made taking the price of reference of export of Crude in the respective Sea Terminal, reported for the month in which the loss or damage of Crude occurs, based on the commercial balance of ECOPETROL for the export mix of which the Crude was part, discounting the applicable monthly fee for the Services, and including but not limited to, the handling services in plant, storage, terminal services, etc., up to the Point of Entrance of the Pipeline in which the loss or damage of the Crude has occurred. 11.4 Responsibility of the SENDER: 11.5 In those events in which the SENDER may be involved, the technical procedures defined for these occasions by ECOPETROL shall be followed: 11.6 Procedure under an Excusable Event: In the event of occurrence of an Excusable Event: e) Save the event of gross negligence or willful misconduct, if any claims arise by the SENDER such as the loss of profit, this shall not exceed twenty five percent (25%) of the value that ECOPETROL is obliged to indemnify the SENDER under this numeral 11.2(d) of the Contract hereof. a) The SENDER shall be liable for any damage caused to ECOPETROL for the default of its obligations under the Contract hereof and shall be responsible for any damage derived from or as a consequence of the actions or omissions of the SENDER, its workers, subordinates, contractors and subcontractors, except in cases of (i) gross negligence or willful misconduct by ECOPETROL, or (ii) a force majeure or unforeseen circumstances. b) The SENDER shall not be waved from its responsibility to pay the Fee agreed in this Contract, save the Service is not provided by causes exclusively attributable to ECOPETROL as indicated in numeral 11.2 b). a) ECOPETROL shall notify the SENDER within twenty four hours (24) following the moment of occurrence, making the commitment to submit all details within the following five (5) business days. 7 11.7 The fulfillment of all legal obligations corresponding to each of the Parties, among them and including, those in connection with its personnel, compliance with environmental standards, those related with the legality of intellectual property rights, tax provisions or any other similar obligation, shall be borne and will be the exclusive
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Extract the exact clause related to "Warranty Duration" from the excerpt above.