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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website www.ual.com united business class united express united airlines airports united reservations united airlines star alliance www.united airlines.com united non-stop flights united fares united packages united airline flight international united travel united and airlines united airlines economy plus United Vacations united airports united airlines tickets united group travel united airlines flights United Escape united express airlines easy update united flights united air vacations unitedair united fare sale United airfare united last minute fares www.united airlines united efares untied airlines united getaways www.unitedairlines united low fares united airline.com united airlines bookings united air line cities united flies united airlines travel fly on united united airlines homepage united airlines group travel united airlines website united airlines travel certificates united destinations United Easy Update united airline flights united airlines business travel united airlines home page united special deals United airfares united business travel e-fares untiedair united airlines site united economy class united airlines fares united package deals www.unitedairline.com international united ticket united airlines home international united tickets united airlines vacations shop for united flights vacation travel United EasyUpdate united specials fly with united www.united airline.com united e fares unitied airlines united travel certificates united deals united air star alliance international united flight united fare search united airlines online United Escapes united e-fares international united flight united airlines cities united airlines online united air fare united e-fares united airlines reservations online united airlines cities united airline fare Source: CREDITCARDS.COM, INC., S-1, 8/10/2007 Continental Restricted Key Words Continental airlines Continental air fare Continental Continental airlines reservations online continental.com Continental airline fare continental airline international Continental flights www.continental.com Continental air continental flight Continental first class continental air lines Continental Vacation continental airlines schedule Continental travel continental airline travel Continental airlines specials continental reservation Continental discounts continental reservations Continental trip continental fares travel with Continental continental airline flight Continental airlines discounts continental and airlines Continental airlines official website Continental Vacations Continental business class continental airlines tickets Continental airlines airports continental airlines flights Continental non stop flights continental flights continental airlines Continental packages continental air line International Continental travel continental airlines travel Continental airports continental airlines homepage Continental group travel continental airlines website Continental air vacations continental destinations Continental fare sale continental airlines vacations Continental last minute fares continental air fare Continental getaways continental airlines reservations online Continental low fares continental airline fare Continental airlines bookings international continental flight cities Continental flies continental airlines online fly on Continental continental airlines cities Continental airlines group travel Continental economy class Continental airlines travel certificates Continental package deals Continental airlines business travel international Continental ticket Continental special deals international Continental tickets Continental business travel shop for Continental flights fly with Continental Source: CREDITCARDS.COM, INC., S-1, 8/10/2007
"""

Extract the exact clause related to "Anti-Assignment" from the excerpt above.

assistant: Not found.