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:
"""
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 (a) job listings for inclusion, at VerticalNet's reasonable business discretion and at VerticalNet's then current listing rate, in the Co-Branded Career Center or on any other VerticalNet Site except a Site co-branded with a PaperExchange Competitor (the "PaperExchange Career Content") and (b) equipment listings for inclusion, at VerticalNet's reasonable business discretion and at VerticalNet's then current listing rate, in the Co-Branded Equipment Listings or on any other VerticalNet Site except a Site co-branded with a PaperExchange Competitor (the "PaperExchange Equipment Content", and together with the PaperExchange Career Content, the "PaperExchange Content"). PaperExchange shall not provide such PaperExchange Content to VerticalNet until the third party placing the listing has agreed to VerticalNet's then current terms and conditions, subject to final approval by VerticalNet. PaperExchange shall provide the PaperExchange Content in the form of the templates attached hereto as Exhibits B and C. Any listings placed on the Co-Branded Sites (or other VerticalNet Site as permitted in this Section 2.2 [CO-BRANDED CAREER CENTER AND CO-BRANDED ...]) by a user that entered the Co-Branded Site or permitted VerticalNet Site, as applicable, from a PaperExchange Site or from a Link to Pulp and Paper Online jointly placed by VerticalNet and PaperExchange, or placed solely by PaperExchange, on a third party's Site shall be treated as "PaperExchange Content" for all purposes of this Agreement. VerticalNet shall be responsible for, and shall have sole control of, all credit, billing and collection in connection with the PaperExchange Content. PaperExchange shall have no authority to make collections on behalf of VerticalNet. 2.3. PaperExchange hereby grants VerticalNet an exclusive license to use, modify, enhance, reproduce, display, perform and transmit the PaperExchange Content, subject to and in accordance with the terms, conditions and provisions of this Agreement. VerticalNet shall not disclose, transfer or otherwise provide the PaperExchange Content to any third party, including, but not limited to, any PaperExchange Competitor, except as otherwise permitted under this Agreement. 4 2.4. PaperExchange shall, at PaperExchange's sole cost and expense, place Links on the PaperExchange Home Page labeled "Career Center" and "Equipment Listings" (or mutually agreeable substitutes for such terms) in a mutually agreeable location and size that will directly transfer users to the Co-Branded Sites. 2.5. VerticalNet, in its reasonable business discretion, shall market the Co-Branded Sites on Pulp and Paper Online, at pulp and paper industry trade shows, in its print advertisement campaigns and through its sales force. Such marketing activities shall be at VerticalNet's sole cost and expense. 2.6. PaperExchange, in its reasonable business discretion, shall market the Co-Branded Sites on the PaperExchange Home Page, at pulp and paper industry trade shows, in its print advertisement campaigns and through its sales force. Source: PAPEREXCHANGE COM INC, S-1/A, 3/22/2000 Such marketing activities shall be at PaperExchange's sole cost and expense. 2.7. VerticalNet will provide, install, repair, maintain and pay for the communications, computer and peripheral equipment, services and facilities supporting the Co-Branded Sites. VerticalNet shall maintain the Co-Branded Sites in a high quality and professional manner consistent with its maintenance of other VerticalNet Sites. VerticalNet and PaperExchange shall be responsible for the sale of all advertising on the Co-Branded Sites; provided, however, that neither party shall sell advertising on the Co-Branded Sites to a competitor (as defined in 1.16 and 1.25) and provided that each party shall submit any proposed advertising for the Co-Branded Sites to the other party for its prior written approval, such approval not to be unreasonably withheld, delayed or conditioned. 2.8. VerticalNet shall be solely responsible for the development, operation and maintenance of Pulp and Paper Online and for all materials that appear on Pulp and Paper
"""

Extract the exact clause related to "Document Name" from the excerpt above.