A reservation of rights is a statement by which a party declares that something it is doing - paying an invoice, defending a claim, appearing in court, publishing a web page - should not be read as giving up a legal right, claim or defence it holds. Common law courts treat conduct as a choice: a party that keeps performing after a breach may be held to have affirmed the contract. The reservation is the written record that no such choice was made.

The phrase carries a second, newer meaning in European copyright law, where a "reservation of rights" is the opt-out that removes online content from the text and data mining exception relied on by AI developers.

How a reservation works

Three legal doctrines create the need for it. Waiver is the voluntary surrender of a known right. Election forces a party with a choice, such as terminating or continuing a contract, to pick one, and treats unequivocal conduct as the pick. Estoppel prevents a party from going back on a position another party relied on.

It appears in three main forms. The first is a contract clause. Licences usually reserve all rights not expressly granted, and many agreements add a "no waiver" clause. The second is a letter or notice sent while a dispute is live. The third is a court filing, where a party participating in proceedings preserves objections it would otherwise lose by participating.

In the United States, the Uniform Commercial Code gives the device statutory form. Section 1-308 provides that a party that "with explicit reservation of rights performs or promises performance or assents to performance" in a manner demanded by the other side "does not thereby prejudice the rights reserved", and that words such as "without prejudice" or "under protest" are sufficient, according to the Cornell Legal Information Institute's text of the code. The section, numbered 1-207 before the 2001 revision of Article 1, does not apply to an accord and satisfaction.

A worked example from October 2026 shows the court-filing form at its most granular. When Character Technologies, the company behind Character.ai, entered Chapter 11 in the District of Delaware (case 26-11603, Judge Brendan Linehan Shannon), Disney filed a notice of appearance on October 13. Its reservation paragraph kept Disney's right to a jury trial, to an Article III judge, to de novo review in non-core matters and to setoff and recoupment under its agreements with the debtor. In Stern v. Marshall in 2011 the Supreme Court held that a bankruptcy judge lacks constitutional authority to enter final judgment on certain state law counterclaims, and in Wellness International Network v. Sharif on May 26, 2015 it held that parties can consent to that authority impliedly, provided consent is "knowing and voluntary", according to Dechert. Appearing without reserving invites the argument that consent was given by conduct.

Insurance and the reservation of rights letter

Insurance produced the best-known form. Under a liability policy, an insurer that doubts cover still usually owes a duty to defend. It can defend while sending a reservation of rights letter, preserving its ability to deny coverage later.

The device creates a conflict. In San Diego Navy Federal Credit Union v. Cumis Insurance Society, decided on December 3, 1984, a California appeal court held that where a reservation creates divergent interests between insurer and insured, the insurer must pay for independent counsel chosen by the insured. California's legislature codified the rule in Civil Code section 2860 in 1987, according to Wikipedia's summary of the case.

Courts increasingly demand specificity. On January 11, 2017, the South Carolina Supreme Court held in Harleysville Group Insurance v. Heritage Communities that letters quoting policy language without explaining the insurer's position were inadequate, and the insurer lost the right to contest about $11 million in actual damages, according to Cozen O'Connor. In a January 2012 survey by Airmic, the association of corporate insurance buyers, 33% of members had received at least one such letter in two years, and 62% believed the letters were issued unfairly, according to Airmic's guide.

Copyright gave the phrase its most familiar wording. The Buenos Aires Convention of 1910 protected works across signatory states only if they carried a statement reserving the property right, which is why books still print "All rights reserved". The formality became essentially obsolete on August 23, 2000, when Nicaragua, the last Buenos Aires member outside the Berne Convention, joined Berne, according to Wikipedia.

The European Union revived the concept in 2019. Article 4 of the Directive on Copyright in the Digital Single Market (2019/790), adopted on April 17, 2019, allows text and data mining of lawfully accessible works for any purpose, but under Article 4(3) only where use "has not been expressly reserved by their rightholders in an appropriate manner, such as machine-readable means in the case of content made publicly available online", according to the text of the directive. Member states had until June 7, 2021 to transpose it.

The AI Act turned the opt-out into a compliance target. Article 53(1)(c) requires providers of general-purpose AI models to identify and comply with reservations expressed under Article 4(3), an obligation applicable from August 2, 2025 and supervised by the AI Office. The General-Purpose AI Code of Practice, published on July 10, 2025, commits signatories to crawlers that follow robots.txt as part of procedures for honouring rights reservations. The Commission consulted on further machine-readable protocols until January 9, 2026 and has said it will publish a list of generally agreed solutions, according to the Society for Computers and Law.

Cloudflare's Content Signals Policy, announced on September 24, 2025, added search, ai-input and ai-train preferences to the managed robots.txt of more than 3.8 million domains, and states that restrictions expressed through the signals "are express reservations of rights under Article 4", according to Cloudflare. Czech industry body SPIR published a standard on March 19, 2026 that ties robots.txt tokens for AI crawlers to Article 4(3). Vendor tokens such as Google-Extended work similarly without the legal wording.

Why it matters for advertising

The marketing industry meets the term in three places. Litigation over ad tech is full of reservations. In the October 2, 2026 proposed final judgment in the Justice Department's ad tech case against Google, the plaintiffs' draft included a reservation-of-rights clause in Section XIII reserving other claims, which Google's draft omits. Whether the decree forecloses later claims matters to publishers harmed by conduct found unlawful in April 2025.

Bankruptcy is the second. Advertisers, agencies and vendors become creditors and counterparties when ad tech companies fail, as when Sizmek filed for Chapter 11 in 2019. Data sales such as Google's $10 million purchase of Spirit Airlines' customer data draw objections that routinely close with reservations. Disney's filing in Character.ai matters because its $20 million bid licenses intellectual property rather than buying the app, and setoff rights could shape the final accounting.

Publishing is the third. In the EU, the Article 4(3) reservation is the legal hook that turns a crawler block into an enforceable opt-out.

Limits and disputes

A reservation cannot create a right that did not exist, and it cannot override conduct. In Tele2 International Card Company v Post Office on January 28, 2009, the English Court of Appeal held that the Post Office had elected to affirm a contract by waiting about 11 months to terminate after Tele2 missed a guarantee deadline. Its no-waiver clause did not help: Lord Justice Aikens said the clause "cannot prevent the fact of an election to abandon the right to terminate from existing", according to Pinsent Masons.

Boilerplate is the second weakness: Harleysville shows a generic reservation may count for nothing.

The copyright version carries the sharpest dispute: what "machine-readable" means. Hamburg's Regional Court suggested on September 27, 2024 that a reservation in natural language in website terms could qualify, because AI systems can read text, according to Legal Tribune Online. The Hanseatic Higher Regional Court took the opposite view on December 10, 2025, holding the photographer's opt-out invalid because it was not machine-readable, and allowed an appeal to the Federal Court of Justice, according to Hogan Lovells. Protocol-based reservations also work only if crawlers identify themselves honestly.

Not the same as

Without prejudice (English law). In England, "without prejudice" marks settlement communications as inadmissible in evidence. Under UCC section 1-308 the same words reserve rights.

No-waiver clause. A standing contract term about future delay or forbearance. A reservation of rights is usually a specific statement about a specific act,.

Opt-out signal. A browser or device message refusing the sale or sharing of personal data, such as Global Privacy Control. The opt-out signal is sent by a reader under privacy law; a rights reservation is made by a rightsholder under copyright law.

Reservation buying. In media trading, a reservation is a guaranteed booking of inventory, as in programmatic guaranteed deals. It has no connection to legal rights.

Recent developments

The machine-readable reservation proved fragile in 2026. HasData found that 118 Cloudflare-proxied sites, including the Smithsonian and Bellingcat, lost the managed robots.txt lines carrying an Article 4 reservation and an ai-train=no signal by September 16, 2026, although 16 of 21 tested sites still blocked GPTBot at the network level. The Court of Justice of the European Union heard Like Company v Google (C-250/25), its first generative AI copyright reference, which asks whether chatbot training falls within Article 4, on March 10, 2026, according to Bird and Bird. No judgment had been reported as of October 2026. The Character.ai sale hearing is set for November 24, 2026.

Timeline

  • 1910: Buenos Aires Convention requires a statement reserving property rights, the origin of "All rights reserved"
  • December 3, 1984: Cumis decision requires insurers reserving rights to fund independent counsel in California
  • 1987: California codifies the rule in Civil Code section 2860
  • August 23, 2000: Nicaragua joins Berne, making the Buenos Aires notice largely obsolete
  • 2001: Revised UCC Article 1 renumbers the reservation provision as section 1-308
  • January 28, 2009: Court of Appeal rules in Tele2 v Post Office that a no-waiver clause cannot stop an election
  • 2011: Stern v. Marshall limits bankruptcy judges' authority to enter final judgments
  • January 2012: Airmic survey finds 62% of members thought reservation letters unfair
  • May 26, 2015: Wellness v. Sharif allows implied consent to bankruptcy court adjudication
  • January 11, 2017: Harleysville sets specificity requirements for reservation letters in South Carolina
  • April 17, 2019: EU adopts Directive 2019/790, with the Article 4(3) reservation
  • June 7, 2021: Transposition deadline for Directive 2019/790
  • September 27, 2024: Hamburg Regional Court suggests natural-language reservations may be machine-readable
  • July 10, 2025: General-Purpose AI Code of Practice published
  • August 2, 2025: AI Act obligations for general-purpose model providers apply
  • September 24, 2025: Cloudflare launches the Content Signals Policy
  • December 10, 2025: Hanseatic Higher Regional Court requires machine-readable reservations
  • January 9, 2026: Commission consultation on opt-out protocols closes
  • March 10, 2026: CJEU hears Like Company v Google
  • March 19, 2026: SPIR publishes Czech robots.txt standard tied to Article 4(3)
  • October 2, 2026: Proposed final judgment in US v. Google (ad tech) filed with disputed reservation clause
  • October 13, 2026: Disney reserves jury trial and setoff rights in Character.ai bankruptcy

Summary

Who: Contracting parties, insurers and policyholders, creditors and litigants, and, in the EU, copyright holders and publishers reserving content from AI developers. Courts, the AI Office and infrastructure providers such as Cloudflare shape how reservations are read.

What: A statement that an act, payment, filing or publication does not waive a legal right or claim. In EU copyright law, an express, machine-readable opt-out from the commercial text and data mining exception.

When: Rooted in copyright formalities from 1910 and codified in UCC section 1-308 (formerly 1-207); the EU text and data mining version dates from April 17, 2019 and gained force through AI Act obligations applicable from August 2, 2025.

Where: In contract clauses, insurance letters, court filings such as Disney's October 13, 2026 notice in Delaware, and robots.txt files on publishers' sites.

Why: Waiver, election and estoppel can strip a party of rights through conduct alone. A clear, specific and timely reservation is the main defence, though courts have repeatedly held that it cannot outweigh conduct that shows a choice.