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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foreign equivalents to any of the foregoing. "PDF" means Adobe™ Portable Document Format sent by electronic mail. "Permitted Sublicensee" has the meaning set forth in Section 2.1(b). "Person" means an individual, sole proprietorship, partnership, limited partnership, limited liability partnership, corporation, limited liability company, business trust, joint stock company, trust, incorporated association, joint venture or similar entity or organization, including a government or political subdivision or department or agency of a government or other Governmental Authority. "Pfizer" means Pfizer Inc., a Delaware corporation. "Potential New Field" has the meaning set forth in Section 2.1(c). "Pricing and Reimbursement Authority" means, as applicable, the body with the authority to control, approve, recommend, decide, or otherwise determine pricing and reimbursement of pharmaceutical products, including those with authority to enter into risk sharing schemes or to impose retroactive price reductions, discounts, or rebates (including the National Institute for Health and Care Excellence and the Scottish Medicines Consortium in the U.K.; the Institute for Quality and Efficiency in Health Care in Germany; the Technical Scientific Commission and the Price and Reimbursement Committee within the Italian Medicines Agency in Italy; the Directorate General for the Basic Portfolio of the National Health and Pharmacy System of the Ministry of Health in Spain; the National Union of Health Insurance Funds and the National Authority of Health in France; and Health Canada in Canada) or non-governmental authority (including "Sick Funds" in Germany)). "Pricing Approval" means the approval, agreement, determination or decision establishing prices for Product that can be charged in countries where Governmental Authorities or their designees control, approve, recommend, decide, or otherwise determine the price of pharmaceutical products. "Product" means the FDA-approved oral formulation of TPOXX® (tecovirimat) for use in the Field, or any oral formulation of tecovirimat for use in the Field for which a Regulatory Authority grants Drug Approval to SIGA in a country or jurisdiction in the Territory. 7 Source: SIGA TECHNOLOGIES INC, 8-K, 6/3/2019 "Promote" or "Promotion" means to market, advertise, promote, offer for sale, or sell a product. "Promotion Fee" has the meaning set forth in Section 6.1(a). "Purchase Order" shall mean a written purchase order generated by MMT for Product to be delivered pursuant to Customer Contracts which includes the information set forth in Section 5.2(a). "Quarterly Collected Revenue" means Net Product Sales Amount that is collected during the applicable Calendar Quarter. "Quarterly Payment" has the meaning set forth in Section 6.2(a). "Quarterly Report" has the meaning set forth in Section 6.2(a). "Regulatory Approval" means, with respect to the Product in a particular country in the Territory, marketing authorization granted by the relevant Regulatory Authority permitting the marketing and sale of the Product in such country but excludes any and all Pricing Approvals and Reimbursement Approvals. "Regulatory Authority" means, in a particular country, the Governmental Authority with the authority to grant Regulatory Approval in such country. "Regulatory Materials" means any documentation comprising any regulatory application, submission, notification, communication, correspondence, proof of approval or license, registration, Regulatory Approval or other filing made to, received from or otherwise conducted with a Regulatory Authority to Develop, Manufacture, market, sell or otherwise Commercialize the Product in a particular country in the Territory. "Reimbursement Approval" means the approval, agreement, determination or decision regarding the prices for Product that can be reimbursed in jurisdictions where the applicable Pricing and Reimbursement Authority approves, determines or recommends the reimbursement of pharmaceutical products. "Renewal Term" has the meaning set forth in Section 11.1. "Restricted Markets" means, as applicable under Global Trade Control Laws, the Crimean Peninsula, Cuba, Iran, North Korea, and Syria. "Restricted Party" means any individual(s) or entity(ies) on any of the following (collectively referred to herein as the "Restricted Party Lists"): the list of sanctioned entities maintained by the UN; the Specially Designated Nationals List and the Sectoral Sanctions Identifications List, as administered by the U.S. Department of the Treasury Office of Foreign Assets Control; the U.S. Denied Persons List, the U.S. Entity List, and the U.S. Unverified List, all administered by the U.S. Department of Commerce; the entities subject to restrictive measures and the Consolidated List of Persons, Groups and Entities Subject to E.U. Financial Sanctions, as implemented by the E.U. Common Foreign & Security Policy; the List of Excluded Individuals / Entities, as published by the U.S. Health and Human Services - Office of Inspector General; any lists of prohibited or debarred parties established under the U.S. Federal Food Drug and Cosmetic Act; the list of Persons and entities suspended or debarred from contracting with the U.S. government;
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Extract the exact clause related to "Irrevocable Or Perpetual License" from the excerpt above.