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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which Source: LEADERSONLINE INC, S-1/A, 4/27/2000 such revenue was received by LeadersOnline. Such payments shall be accompanied by a statement containing reasonable detail of the number of VerticalNet-Leaders Online Clients generated during the month, the type and number of transactions from which the LeadersOnline VerticalNet Revenue was derived, the total LeadersOnline VerticalNet Revenue for such period and the total fees payable to VerticalNet pursuant to this Section 6.3.1 [Revenue Sharing]. 6.3.2. LeadersOnline shall pay VerticalNet a one time fee for each Candidate who is offered and accepts employment as a result of a contact made by LeadersOnline (each a "Placement"). The fee shall be payable upon receipt by LeadersOnline of its payment for the Placement, and shall be nonrefundable. Fees shall be based upon the annual salary (or hourly rate multiplied by 2080) of the Candidate accepting employment in the Placement in accordance with the following schedule: 6.3.2.1. $*** for Placements involving annual salaries of less than $***; 6.3.2.2. $*** for Placements involving annual salaries of $*** up to and including $***; and ___________ *** Omitted pursuant to a confidential treatment request filed separately. 6 6.3.2.3. $*** for Placements involving annual salaries of $*** or greater. 6.3.3. VerticalNet shall institute procedures to track information of Users of the VerticalNet Sites that utilize a Link to access the LeadersOnline Site. LeadersOnline agrees to add a request in its standard registration form to identify those Users who have accessed the LeadersOnline Site based upon information contained in any promotional materials with respect to LeadersOnline on a VerticalNet Site, including any Banner, Newsletter Ad or Employer Spotlight identifying LeadersOnline, and to maintain such information in a form that can be examined by VerticalNet pursuant to Section 6.6 [Audits]. 6.3.4. If government regulations prevent LeadersOnline from sharing any revenues associated with LeadersOnline Services, VerticalNet and LeadersOnline shall negotiate in good faith a compensation structure that seeks to provide VerticalNet with compensation equal to that set forth in Sections 6.3.1 [Revenue Sharing]. and 6.3.2. 6.4. Taxes. All payments required under this Agreement are exclusive of federal, state, local and foreign taxes, duties, tariffs, levies and similar assessments. When applicable, such taxes shall appear as separate items on a Party's invoice or statement to the other Party. Payment of such taxes or charges shall be the responsibility of the Party whose obligation it is under this Agreement to make the payment in respect of which such taxes are assessed, excluding any taxes based upon the other Party's net income. In lieu thereof, a Party shall provide the other Party with a tax or levy exemption certificate acceptable to the taxing or levying authority. 6.5. Guaranteed Revenues. VerticalNet agrees to guarantee that, during the initial Term of this Agreement, LeadersOnline shall earn LeadersOnline- VerticalNet Revenue of at least *** Dollars ($***) (the "Guaranteed Amount"), subject to the provisions of this Section 6.5 [Guaranteed Revenues]. *** Within thirty (30) days after the end of the initial Term, LeadersOnline shall submit a statement showing a reasonably detailed accounting of the LeadersOnline-VerticalNet Revenue received during the initial Term (or earned during the initial Term and paid within 30 days thereafter) along with payment of all such amounts up to the Guaranteed Amount. In the event this Agreement is terminated in accordance with Section 7.1 [DEFINITIONS], LeadersOnline shall make a payment of all amounts of LeadersOnline- VerticalNet Revenues received through the date of termination, up to the amount of the Guaranteed Amount ***. 6.6. Audits. During the 12 month period following the payment of any amount due under this Article 6, VerticalNet or its representative shall have the right to audit LeadersOnline's financial and other pertinent records relating to such payment in order to verify the amount of the payments owed and/or paid. If the amount owed by LeadersOnline to VerticalNet was underpaid, the additional amount owed shall be paid to VerticalNet within 15 days of notice of such underpayment to LeadersOnline. If the amount owed by LeadersOnline to VerticalNet was underpaid in excess of 10% of the amount owed, the fees of such audit shall also be paid to VerticalNet within 15 days of notice of such to LeadersOnline. If the amount owed by LeadersOnline to ___________ *** Omitted pursuant to a confidential treatment request filed separately. 7 VerticalNet was overpaid, the excess amount paid shall be returned by VerticalNet within 15 days of notice of such overpayment. VerticalNet shall give reasonable advance notice to LeadersOnline of such audit and each audit shall be conducted in a manner that does
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Extract the exact clause related to "Irrevocable Or Perpetual License" from the excerpt above.

assistant: Not found.