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:
"""
VerticalNet Site or the VerticalNet Area of the Co-Branded Site violates, infringes or misappropriates any Intellectual Property Right of any third party and (ii) pay all costs, expenses and disbursements authorized by the Indemnitor (defined below) incurred in such defense, and any damages, liabilities, obligations, penalties or judgments awarded in any such action, or any settlement amount agreed to by VerticalNet. 11 9.6. PROCEDURE. If any action shall be brought against a party in respect to which indemnity may be sought from the other party pursuant to the provisions of this Article 9 [DISCLAIMER OF WARRANTY, LIMITATION OF LI...], the party seeking indemnity (the "Indemnitee") shall follow the procedures in this Section. If an Indemnitee receives any notice of a claim or other allegation with respect to which the other party (the "Indemnitor") has an obligation of indemnity hereunder, then the Indemnitee will, within 15 days of receipt of such notice, give the Indemnitor written notice of such claim or allegation setting forth in reasonable detail the facts and circumstances surrounding the claim. The Indemnitee will not make any payment or incur any costs or expenses with respect to such claim, except as requested by the Indemnitor or as necessary to comply with this procedure. The Indemnitee will not make any admission of liability or take any other action that limits the ability of the Indemnitor to defend the case. The Indemnitor shall immediately assume the full control of the defense or settlement of such claim or allegation, including the selection and employment of counsel, and shall pay all authorized costs and expenses of such defense. The Indemnitee will fully cooperate, at the expense of the Indemnitor, in the defense or settlement of the claim. The Indemnitee shall have the right, at its own expense, to employ separate counsel and participate in the defense or settlement of the claim; provided that the Indemnitor shall have no liability for costs or expenses incurred by the Indemnitee, except to the extent authorized by the Indemnitor pursuant to this procedure. 9.7. ESSENTIAL PART OF BARGAIN. The parties acknowledge that the disclaimers and limitations set forth in this Article 9 [DISCLAIMER OF WARRANTY, LIMITATION OF LI...] are an essential element of this Agreement between the parties and that the parties would not have entered into this Agreement without such disclaimers and limitations. Source: IMPRESSE CORP, S-1/A, 3/22/2000 10. MISCELLANEOUS 10.1. INTELLECTUAL PROPERTY. 10.1.1. Except for the express rights granted to Impresse under this Agreement, Impresse acknowledges and agrees that the Intellectual Property of VerticalNet is and shall remain the sole property of VerticalNet and nothing in this Agreement shall confer in Impresse any right of ownership or license rights in VerticalNet's Intellectual Property. In addition, Impresse shall not now or in the future contest the validity of VerticalNet's ownership of its Intellectual Property; provided, however, that Impresse may contest the validity of VerticalNet's Intellectual Property in any proceeding brought against Impresse alleging infringement or misappropriation of VerticalNet's Intellectual Property. 10.1.2. Except for the express rights granted to VerticalNet under this Agreement, VerticalNet acknowledges and agrees that the Intellectual Property of Impresse is and shall remain the sole property of Impresse and nothing in this Agreement shall confer in VerticalNet any right of ownership or license rights in Impresse's Intellectual Property. In addition, VerticalNet shall not now or in the future contest the validity of Impresse's ownership of its Intellectual Property; provided, however, that VerticalNet may contest the validity of Impresse's Intellectual Property in any proceeding brought against VerticalNet alleging infringement or misappropriation of Impresse's Intellectual Property. 12 10.2. GOVERNING LAW. This Agreement shall be governed by and interpreted under the laws of the State of Delaware without regard to its conflicts of law provisions. 10.3. NO ASSIGNMENT. Except as otherwise set forth herein, neither party shall transfer, assign or cede any rights or delegate any obligations hereunder, in whole or in part, whether voluntarily or by operation of law, without the prior written consent of the other party, which consent may be withheld at the other party's reasonable business discretion; provided, however, that either party may transfer this Agreement without prior written consent of the other to an Affiliate of such party, or to the surviving party in a merger or consolidation, or to a purchaser of all or substantially all of its assets. 10.4. GOOD FAITH. The parties undertake to display to each other the utmost good faith, consistent with their respective rights and obligations set forth in this Agreement. 10.5. INDEPENDENT CONTRACTORS.
"""

Extract the exact clause related to "Covenant Not To Sue" from the excerpt above.

assistant: In addition, VerticalNet shall not now or in the future contest the validity of Impresse's ownership of its Intellectual Property; provided, however, that VerticalNet may contest the validity of Impresse's Intellectual Property in any proceeding brought against VerticalNet alleging infringement or misappropriation of Impresse's Intellectual Property.