Modification disclaimer
Reusers of Wikimedia content should provide Modification disclaimers to indicate whether they altered or built upon the information or materials extracted from the original sources.
This requirement depends on the license that applies to the specific content being reused. For example, disclaimers are unnecessary when adapting media files in the public domain or under licenses that do not require modification notices. By contrast, altering, translating, or combining text under Creative Commons' Attribution-ShareAlike 4.0 license, which governs most Wikimedia projects, requires explicitly stating whether changes have been made.
Modification disclaimers help promote transparency, since they allow readers to distinguish volunteer‑curated content from derivatives. They also protect Wikimedia's credibility by preventing potential errors introduced downstream from being mistaken as genuine Wikimedia content.
By flagging modifications, reusers can help sustain the credibility and relevance of Wikimedia's open knowledge ecosystem.
Implementation guidance
Minimum requirements
Explicitly state it when the reused content has been modified, edited, translated, mixed, or otherwise adapted in accordance with its license.
Avoid attributing aggregated content to a single Wikimedia project, even when a modification disclaimer is included. (Check the Source signal guidelines for further recommendations on how to attribute in multi-source experiences).
Modifications disclaimers should be included next to the reused content, in a form that is clearly visible or audible, and immediately accessible to the end user.
In visual contexts, include a concise and subtle, yet legible, label such as “Adapted from Wikipedia.”.
In audio or voice contexts, use a short spoken phrase such as “Adapted from Wikipedia” to accompany the modified content.
Best practices
Use clear language to explicitly communicate the type of modification that was applied to the original content (e.g., “Translated from Wikipedia,” “Adapted from Wikipedia,” “Image cropped from Wikimedia Commons”).
Include a link back to the original page in the disclaimer, so users can verify or compare information at the source.
Reuse scenarios
Modification disclaimers support the integrity of content reuse. Without them, mistakes or omissions might be attributed to Wikimedia projects by external audiences. Stating when text, images, or any other media have been modified, or when content has been aggregated before being shared with end users, is essential in scenarios where the applicable license requires modification notices:
Search
Required based on license
Modification disclaimers must be provided whenever the information presented has been adapted from sources. For example, when results alter original phrasing or aggregate content (e.g., in AI-generated results).
AI assistants
Required based on license
Declaring modifications in AI contexts is essentual to prevent users from confusing AI-generated text by volunteer‑curated content.