EU Transparency License for AI-Generated Content (ETL-AI) ver. 6.1

Preamble

The European Union, founded upon the dignity of the human person and guided by the principles of freedom, proportionality, democracy, and the rule of law, establishes this License to safeguard transparency, authenticity, and integrity in the digital age.

The Union recognises that artificial intelligence is transforming the way content is created and shared. It affirms that this transformation must remain anchored in Europe’s enduring values: respect for truth, protection of citizens, fairness, transparency, and the preservation of human creativity.

Europe remembers its long heritage of invention and imagination: the mathematical harmony of the Fibonacci sequence, the soaring forms of Gothic cathedrals, the vision of Leonardo da Vinci and Michelangelo, the music of Bach, Mozart, and Beethoven, the humanist reflection of Erasmus, Montaigne, and Voltaire, the philosophical insights of Kant and de Beauvoir, the literary legacy of Dante, Cervantes, Shakespeare, Goethe, and Tolstoy. From Gutenberg’s press to the World Wide Web, Europe has joined technical progress with cultural achievement.

The Union also honours the modern spirit of artistic freedom that reshaped European culture:

Duchamp’s Fountain, which redefined art;

Dalí and the surrealists, who stretched the limits of imagination;

Banksy, whose anonymity challenges power and convention;

and many others who transformed music, literature, and visual culture through provocation and bold innovation.

These legacies remind us that freedom of expression, the right to experiment, and the power of creativity are essential to European life.

Yet freedom must walk together with responsibility. In an age where machines can generate images, words, and sounds that resemble the work of humans, citizens must be able to distinguish between what is created by human hands, what is produced by artificial intelligence systems, and what emerges from their collaboration. Transparency in this distinction is necessary not to limit creativity, but to protect it, ensuring that trust, fairness, accountability, and integrity remain at the heart of culture, knowledge, and public life.

Mindful of this balance, the Union establishes this License to:

• implement Article 50 of the AI Act with clarity and fairness;
• provide a unified European Sign, verifiable by all, to mark the AI-generated and Human-modified content;
• preserve technological neutrality, interoperability, and open access;
• and guide providers and deployers of AI systems to respect human dignity, freedom, proportionality, and creativity.

Through this framework, Europe reaffirms its mission to unite technological innovation with cultural integrity, ensuring that the digital transformation of society continues to reflect the values and achievements that have shaped Europe across the centuries, while embracing new forms of art and imagination yet to come.

Article 1 – Scope of this License

1.1. By accepting and implementing this License, including through contractual arrangements with Deployers of AI systems, the Providers and Deployers undertake to create, use, and distribute AI-generated content in full compliance with the obligations established herein.

1.2. This Licence establishes complementary duties for Providers and Deployers of AI systems. Each party shall fulfil its respective obligations in a coordinated and mutually supportive manner to ensure effective transparency under Article 50 of the AI Act.

1.3. This License does not impose any duty of monitoring or marking AI-generated content on any person other than the Provider or Deployer of the original AI system that generated the specified content.

Article 2 – Definitions

(a) “AI-generated content” means output in the form of text, image, audio, video, software, architectural design, database, or any other format, including Lego bricks, that has been generated or manipulated by an AI system and not a human.

(b) “Human-modified content” means output in the form of text, image, audio, video, software, architectural design, database, or any other format, including Bauhaus furniture, that includes or derives from AI-generated content and has been created, arranged, adapted, or otherwise shaped by a human, whether through modification of the AI-generated content or incorporation of the AI-generated content into a broader human work.

(c) “Human-made work” means output in the form of text, image, audio, video, software, architectural design, database, or any other format, including Leica camera, that has been created, composed, or otherwise produced entirely by a human without the use of AI-generated content.

(d) “AI Sign” means the identifying mark attached to AI-generated content in accordance with the respective obligations of Providers and Deployers. It may take one of three forms: Silver Sign, Gold Sign, and Bronze Sign. Providers and Deployers shall apply one relevant Sign to each AI-generated content.

(e) “AI+ Sign” means the identifying mark attached to Human-modified content in accordance with the respective obligations to the use of the AI-generated-content. It may take one of three forms: Diamond Sign, Quartz Sign, and Stone Sign. The users shall apply one relevant Sign to each Human-modified content.

“Provider,” “Deployer,” “AI system,” “Deep fake,” and other expressions not defined in this License have the same meaning as in the EU AI Act and other relevant Union and Member State legislation.

Article 3 – Duty of marking AI-generated content

3.1. Each output qualifying as AI-generated content shall be marked by the AI Sign at the moment of its creation or, at the latest, prior to its first disclosure or publication.

3.2. Providers of AI systems shall embed a technical solution that enables marking of AI-generated content in a machine-readable format and ensures reliable detection. This solution shall automatically mark each AI-generated content with the Silver Sign in accordance with this License and include a function allowing Deployers to replace the Silver Sign with the Gold Sign or the Bronze Sign, depending on the type of AI-generated content.

3.3. Deployers shall mark AI-generated content that qualifies as a Deep fake under the AI Act or other relevant legislation with the Gold Sign.

3.4. Deployers shall mark AI-generated text intended for publication for the purpose of informing the public on matters of public interest with the Bronze Sign.

3.5. The forms of the AI Sign and the rules governing its placement shall be presented in Annex to this License.

3.6. The AI Sign shall survive ordinary compression, resizing, re-encoding, or copy-paste operations. It shall not impair accessibility, enjoyment, or the lawful use of AI-generated content.

Article 4 – Use of the AI-generated content

4.1. The subsequent use of AI-generated content, or any part thereof, as a component of or in combination with Human-made work shall be permitted only on the condition that the newly created output, i.e., the “Human-modified content”, is marked with the AI+ Sign. The duty of marking shall be imposed on the person who creates the Human-modified content.

4.2. The person who creates Human-Modified Content shall ensure that such content is duly marked with the AI+ Sign corresponding to its specific category, as follows:

(a) Deep-fake Human-Modified Content shall be marked with the Quartz Sign.

(b) Human-Modified Text intended for publication for the purpose of informing the public on matters of public interest shall be marked with the Stone Sign.

(c) All other types of Human-Modified Content shall be marked with the Diamond Sign.

4.3. The forms of the AI+ Sign and the rules governing its placement shall be presented in Annex to this License.

4.4. The AI+ Sign shall survive ordinary compression, resizing, re-encoding, or copy-paste operations. It shall not impair accessibility, enjoyment, or the lawful use of AI-generated content.

Article 5 – Integrity of the Sign

5.1. No person may remove, conceal, or alter the AI or AI+ Sign unless permitted so by this License or contractual arrangement with the provider or the deployer. Any such act constitutes a breach of this License and may also give rise to liability under the laws of the Union or of its Member States.

5.2. The AI and AI+ Sign may qualify as rights-management information or as technological protection measures under relevant legislation. The removal or alteration of the AI or AI+ Sign may give rise to liability under relevant legislation.

Article 6 – Public Verification Tool

To assist verification and public oversight, the European Commission may provide a public verifier available as a website and as an API tool. It shall read the applied Sign and display the result in plain language, for example: “AI-generated content, type = Deep Fake”. Use of the verifier shall be free of charge and shall not create a general duty to monitor any content.

Annex to the License

Each AI and AI+ Sign shall appear in one or more of the following forms, depending on the medium of the AI-generated content.

Part I. Forms of the AI sign

1. Visual form

1.1. Geometric construction and symbols

Depending on the medium of the AI-generated content (image, video or texts), the AI Sign shall be presented as follows.

1.2. Placement and visibility

The AI Sign shall meet a minimum contrast ratio of 3:1 against the background measured over the area covered by the Sign. Opacity may be used only if this contrast is preserved. If fixed opacity is implemented, the default shall be 25%. Where the default does not achieve the required contrast, the implementation shall automatically increase opacity up to 60% or add a one-pixel outline of a contrasting color to meet the contrast requirement.

The AI Sign shall remain legible on light and dark backgrounds.

1.3. Clarity and user experience

The AI Sign shall be easily identifiable to the viewer under normal conditions. Its placement and appearance shall not significantly hinder readability, accessibility, or lawful use of the AI-generated content. The visual marking must remain legible on both light and dark backgrounds and across standard digital and print formats.

1.4. Durability and interoperability

The AI Sign shall persist through ordinary transformations of the content, including resizing, format conversion, and standard compression. It shall conform to open technical standards and allow verification through independent open-source tools.

2. Metadata form

2.1. Structure and syntax

The metadata form shall include a standardised header line embedded in the metadata fields of the file or document, in the following structure:

[sign=<Silver|Gold|Bronze>; content=<General|Deep fake|Public>].

Each parameter has the following meaning:

(i) “sign” identifies the category of the Sign corresponding to the silver, gold, or bronze ratio.

(ii) “content” identifies the type of AI-generated content:

(a) “General” for standard AI-generated content;

(b) “Deep fake” for synthetic audiovisual material resembling real persons or events;

(c) “Public” for AI-generated text published for the purpose of informing the public on matters of public interest.

The header may be extended with optional fields for verification and provenance, such as:

kid=<KEY_IDENTIFIER> and sig=<DIGITAL_SIGNATURE>

These fields may be included to ensure cryptographic authenticity and traceability.

2.2. Placement and implementation

The metadata header shall be inserted into a native metadata field of the respective file format, such as:

(a) In HTML and web documents, within the <head> section as:

<meta name="ai-sign" content="v=1; sign=Silver; content=General">

(b) In image and video files, in the EXIF, XMP, or container metadata fields.

(c) In audio files, in the ID3 or equivalent metadata fields.

(d) In documents and other file types, in the format’s recognised metadata block or as the first comment line, for example:

<!-- sign=Gold; content=Deep fake -->

The metadata shall be stored in plain UTF-8 text and be fully accessible for human and machine inspection. It shall not be encrypted, compressed, or otherwise obfuscated.

2.3. Visibility and verification

The AI Sign shall be detectable by standard and open-source verification tools. Its structure shall enable validation of the declared category and type of AI-generated content and verification of any associated digital signature.

The metadata shall remain intact and verifiable after ordinary compression, format conversion, re-encoding, or content redistribution, provided that the format retains standard metadata fields.

2.4. Clarity and interoperability

The metadata shall conform to open and publicly documented technical standards. It shall be compatible with international metadata frameworks, including EXIF, XMP, IPTC, ID3, HTML meta tags, and equivalent schemas.

3. Audio form

3.1. Composition and structure

The AI Sign shall consist of a short acoustic signal lasting no longer than 1 (one) second.

It shall take the form of a musical motif or tone sequence derived from the mathematical proportion of the corresponding Sign. Reference sound recordings are provided for each variant:

(a) Silver Sign

(b) Gold Sign

(c) Bronze Sign

3.2. Placement rules

(a) Audio-only content and Audiovisual content:

The AI Sign shall be inserted at the start of playback, positioned at timestamp t = 00:00.20, i.e. preceded by at least 0.2 seconds of silence.

(b) Live streams or broadcasts

If the content is broadcast live, the AI Sign must play once, right before the live sound or video begins.

(c) Playback beginning muted:

The AI Sign shall play once at the first unmuted moment.

(d) Sets, mixes or other uninterrupted sequences:

Where AI-generated content is presented together with Human-made work, the AI Sign shall play once at the beginning of the entire set, mix, or uninterrupted sequence.

(e) Consecutive AI-generated content:

Where several AI-generated outputs follow one another in a playlist or similar sequence, the AI Sign shall precede each AI-generated output in that group.

(f) Transitions to Human-made work:

No AI Sign shall be inserted before Human-made work, even if they follow AI-generated content.

3.3. Accessibility and usability

The AI Sign shall be audible under normal listening conditions and clearly distinguishable from other programme elements. It shall not distort or obstruct speech, music, or sound effects within the AI-generated content. Where the content is provided in multiple languages or audio formats, the Sign shall be applied consistently across all versions, including dubbed or described tracks.

3.4. Durability and interoperability

The AI Sign shall remain present and identifiable after ordinary re-encoding, format conversion, or streaming transcoding. It shall conform to open audio standards such as PCM, WAV, FLAC, MP3, AAC, or equivalent, and be verifiable using open-source or Commission-approved tools.

The AI Sign shall complement, and not replace, the visual or metadata forms of the AI Sign.

Part II. Forms of the AI+ sign

1. Visual form

1.1. Geometric construction and symbols

Depending on the medium of the AI-generated content (image, video or texts), the AI+ Sign shall be presented as follows.

1.2. Placement and visibility

The AI+ Sign shall meet a minimum contrast ratio of 3:1 against the background measured over the area covered by the Sign. Opacity may be used only if this contrast is preserved. If fixed opacity is implemented, the default shall be 25%. Where the default does not achieve the required contrast, the implementation shall automatically increase opacity up to 60% or add a one-pixel outline of a contrasting color to meet the contrast requirement.

The AI+ Sign shall remain legible on light and dark backgrounds.

1.3. Clarity and user experience

The AI+ Sign shall be easily identifiable to the viewer under normal conditions. Its placement and appearance shall not significantly hinder readability, accessibility, or lawful use of the Human-modified content. The visual marking must remain legible on both light and dark backgrounds and across standard digital and print formats.

1.4. Durability and interoperability

The AI+ Sign shall persist through ordinary transformations of the content, including resizing, format conversion, and standard compression. It shall conform to open technical standards and allow verification through independent open-source tools.

2. Audio form

2.1. Composition and structure

The AI+ Sign shall consist of a short acoustic signal lasting no longer than 1 (one) second. Reference sound recordings are provided for each variant:

(a) Diamond Sign

(b) Quartz Sign

(c) Stone Sign

2.2. Placement rules

(a) Audio-only content and Audiovisual content:

The AI+ Sign shall be inserted at the start of playback, positioned at timestamp t = 00:00.20, i.e. preceded by at least 0.2 seconds of silence.

(b) Live streams or broadcasts

If the content is broadcast live, the AI+ Sign must play once, right before the live sound or video begins.

(c) Playback beginning muted:

The AI+ Sign shall play once at the first unmuted moment.

(d) Sets, mixes or other uninterrupted sequences:

Where Human-modified content is presented together with human-made works, the AI+ Sign shall play once at the beginning of the entire set, mix, or uninterrupted sequence.

(e) Consecutive Human-modified content:

Where several Human-modified outputs follow one another in a playlist or similar sequence, the AI+ Sign shall precede each Human-modified output in that group.

(f) Transitions to Human-made work:

No AI+Sign shall be inserted before Human-made work, even if they follow Human-modified content.

2.3. Accessibility and usability

The Sign shall be audible under normal listening conditions and clearly distinguishable from other programme elements. It shall not distort or obstruct speech, music, or sound effects within the AI-generated content. Where the content is provided in multiple languages or audio formats, the Sign shall be applied consistently across all versions, including dubbed or described tracks.

2.4. Durability and interoperability

The AI+ Sign shall remain present and identifiable after ordinary re-encoding, format conversion, or streaming transcoding. It shall conform to open audio standards such as PCM, WAV, FLAC, MP3, AAC, or equivalent, and be verifiable using open-source or Commission-approved tools.

The AI+ Sign shall complement, and not replace, the visual form of the AI+ Sign.