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:
"""
signage to be furnished hereunder (the "Signage"), (ii) maintaining the fixed panel structures and (if applicable) the lighting system for the Signage and (iii) furnishing any fan giveaway items to be furnished hereunder (the "Promotional Items") (subject to any limitations with respect thereto as set forth in the Agreement Summary or agreed to by the parties) and any promotional materials prepared by SDBF with respect to the Promotional Items. Sponsorship Agreement- Renewal Sponsor General Provisions Page 2 b. Sponsor shall be responsible, at its sole cost and expense, for (i) the design, production and preparation of all advertising copy and commercial messages to be displayed, published, broadcast or telecast pursuant to this Agreement in accordance with the deadlines established by SDBF, (ii) furnishing to SDBF Sponsor's name, brand names, trademarks, service marks, logos or other identification, for use in or the Promotional Items, promotional materials prepared by SDBF with respect to the Promotional Items, and any advertisements or commercial messages to be furnished hereunder, and (iii) maintaining the advertising copy displayed in or on the Signage in good and attractive order, repair and condition throughout the Term, including the cost of painting or repainting the advertising copy displayed on the Signage to the extent necessary in the reasonable judgment of SDBF. c. All advertising copy and commercial messages displayed, published, broadcast or telecast pursuant to this Agreement, and all characteristics thereof (including without limitation design, layout, elevation, configuration, content, size and color), must be approved in advance by SDBF and Major League Baseball. d. Sponsor shall have the right to change or modify any advertising copy displayed pursuant to this Agreement, subject to SDBF's right of approval of all proposed changes or modifications (and the timing thereof). Any changes or modifications of advertising copy shall be designed, produced and prepared and, if applicable, erected and installed, at Sponsor's sole cost and expense. Sponsor agrees to provide SDBF with all proposed changes or modifications of advertising copy at least thirty (30) days prior to the proposed date of display thereof. 6. Display of Signage. All advertising copy to be displayed on Signage shall be displayed on such Signage (and with respect to Signage designed to be illuminated, illuminated during night events) during all regular-season San Diego Padres baseball games (each, a "Padres Game") scheduled to be played at the ballpark located on Parcel 1 of Parcel Map No. 18855, in the City of San Diego, County of San Diego, State of California, according to the map thereof filed in the Office of the County Recorder or San Diego County, On December 7, 2001 (the "Ballpark") and during other events held at the Ballpark, except for the following in the sole and absolute discretion of SDBF: (1) events during which advertising is prohibited by federal, state or local laws or regulations, (2) events with respect to which the display of the Signage is inappropriate (e.g., religious services, political conventions, television or film production or private events with conflicting interests) or impractical (e.g., events at which staging obscures or prevents the display of Signage), and (3) with respect to illumination, events where blackout conditions are required by the nature of the event (e.g., fireworks displays, concerts, and television or film production). The location, size, content and display of all Signage are subject to all applicable laws, including without limitation any applicable sign ordinance, and subject to Major League Baseball ("MLB") requirements and conditions, whether applicable generally or with respect to specific events such as nationally- televised games, World Baseball Classic games, All-Star Games, playoff games and World Series games and whether applicable to all categories of advertiser or only to certain categories. 7. Use of Trademarks and Service Marks. Sponsor hereby grants to SDBF a limited license to display Sponsor's name, brand names, trademarks, service marks, logos and other identification in or on the Promotional Items, promotional materials prepared by SDBF with respect to the Promotional Items, and any advertisements or commercial messages to be furnished hereunder. Except as expressly provided herein, neither party shall have the right to use, or obtain an interest in, the name, brand names, trademarks, service marks, logos or other identification of the other party or its affiliates without the other party's prior written consent. All advertising or promotional materials displayed, distributed or otherwise used pursuant to this Agreement in conjunction with the name, logos, trademarks, service marks or other identification of the Padres must be approved in advance by the Padres. 8. Indemnity; Insurance; and Assumption of
"""

Extract the exact clause related to "Warranty Duration" from the excerpt above.

assistant: Not found.