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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Site B is the Site to which the user is linked. 1.13. Net Advertising Revenue shall mean the gross amount billed to an advertiser for the sale of advertising on the Third Party Advertising Allocation on the PaperExchange Site, less (a) credits for claims, allowances, retroactive price reductions or returned goods, and (b) sales, excise, use, value-added and other similar taxes (excluding income taxes) actually paid, if applicable. 1.14. Packaging Online shall mean the Site located at www.packagingonline.com (or a successor Site thereto). 1.15. PaperExchange Career Content shall have the meaning ascribed thereto in Section 2.2 [CO-BRANDED CAREER CENTER AND CO-BRANDED ...]. 1.16. PaperExchange Competitor shall mean any exchange, auction or reverse auction for the sale, purchase and/or exchange of pulp, paper and paper packaging. 1.17. PaperExchange Equipment Content shall have the meaning ascribed thereto in Section 2.2 [CO-BRANDED CAREER CENTER AND CO-BRANDED ...]. 1.18. PaperExchange Deliverable shall mean any good, service or other item to be delivered or made available by PaperExchange. 1.19. PaperExchange Home Page shall mean the home page located at the PaperExchange Site. 1.20. PaperExchange Link shall mean a Link that contains a PaperExchange Mark and will take users of other Sites to the PaperExchange Home Page. 2 Source: PAPEREXCHANGE COM INC, S-1/A, 3/22/2000 1.21. PaperExchange Mark shall mean any trademark, service mark, trade name, domain name, design or logo of PaperExchange. 1.22. PaperExchange Revenue shall mean the gross revenue received by PaperExchange from Transaction Fees less (a) credits for claims, allowances, retroactive price reductions or returned goods, and (b) sales, excise, use, value-added and other similar taxes (excluding income taxes) actually paid. 1.23. PaperExchange Site shall mean the Site located at www.PaperExchange.com (or a successor Site thereto). 1.24. Pulp and Paper Online shall mean the Site located at www.pulpandpaperonline.com (or a successor Site thereto). 1.25. Pulp and Paper Online Competitor shall mean any online vertical community portal for professionals in the pulp and paper industry (other than Pulp and Paper Online and PaperExchange). 1.26. Renewal Term shall have the meaning ascribed thereto in Section 8.1 [Automatic Renewal]. 1.27. Site shall mean an Internet World Wide Web site. 1.28. Storefront shall mean a Site contained in (and linked to) a VerticalNet Site that, among other things, provides information regarding an advertiser and the advertiser's products and/or services, links a visitor to the advertiser's website, and/or generates sales leads for the advertiser from interested visitors, but does not include direct e-commerce fulfillment, such as catalog sales. 1.29. Term shall mean the Initial Term and any Renewal Terms. 1.30. Third Party Advertising Allocation shall have the meaning ascribed thereto in Section 4.1 [Advertisements on the PaperExchange Site]. 1.31. Transaction Fees shall mean the fees received by PaperExchange from third parties in consideration for facilitating the purchase and/or sale of pulp and/or paper through the PaperExchange Site. 1.32. VerticalNet Archived Content shall have the meaning ascribed thereto in Section 3.2 [VERTICALNET CONTENT]. 1.33. VerticalNet Content shall have the meaning ascribed thereto in Section 3.1 [VERTICALNET CONTENT]. 1.34. VerticalNet Deliverable shall mean any good, service or other item to be delivered or made available by VerticalNet. 1.35. VerticalNet Link shall mean a Link that contains a VerticalNet Mark and will take users of other Sites to a page of Pulp and Paper Online. 3 1.36. VerticalNet Mark shall mean any trademark, service mark, trade name, domain name, design or logo of VerticalNet. 2. CO-BRANDED CAREER CENTER AND CO-BRANDED EQUIPMENT LISTINGS 2.1. No later than seven days after the Effective Date, VerticalNet shall, at VerticalNet's sole cost and expense, design, develop and implement the Co-Branded Sites with the overall "look and feel" agreed upon by VerticalNet and PaperExchange, as shown in Exhibit A. After the Co-Branded Sites are implemented, VerticalNet shall notify PaperExchange in writing at least five days prior to making any material change to a Co-Branded Site, including, without limitation, a change in the location, sizing or placement of the PaperExchange Links. If PaperExchange does not notify VerticalNet of its rejection of such change within five days, PaperExchange shall be deemed to have approved such change. VerticalNet shall design, host and maintain the Co-Branded Sites at its sole cost and expense. Within 30 days after the Effective Date, VerticalNet and PaperExchange shall agree upon the Co-Branded URLs. The parties shall register the Co-Branded URLs reasonably promptly after the parties have agreed upon them. 2.2. From time to time, PaperExchange shall provide to VerticalNet, at PaperExchange's sole cost and expense, relevant content provided to it by third parties consisting of
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Extract the exact clause related to "Parties" from the excerpt above.