Wikipedia:Attribution does not require blame

Wikipedia's licensing requires that attribution be given to all users involved in creating and altering the content of a page. Wikipedia's page history functionality lists all edits made to a page and all users who made these changes, but administrative deletion actions may remove or hide some of this information. A list of authors satisfies the attribution requirements without providing the specific contributions.

Glossary

• Attribution is the credit that a contributor receives, required by the Wikimedia Foundation's Terms of Use, section 7. Licensing of Content. It should not be confused with attribution of sources as covered by Wikipedia:Attribution.
• Blame is a user's precise contribution, the individual diff in the page history. The term is a tongue-in-cheek reference to the Wikipedia:WikiBlame tool and the git blame command.

List of authors

The Wikimedia Foundation's Terms of Use, section 7.b.iii, specifies a list of authors as a valid attribution method:

Through a list of all authors (but please note that any list of authors may be filtered to exclude very small or irrelevant contributions).

Wikipedia:Copying within Wikipedia § List of authors clarifies its use in practice.

A list of authors does not include page content and cannot provide blame. Therefore, the licensing requirements do not include blame. In January 2022, via email with a Wikipedia administrator, Wikimedia Foundation Legal shared their perspective reaching the same conclusion.

Attribution without full history

Page deletion

Deleted pages may be restored if their content is non-problematic and desired for reuse, but there are alternative methods described in Wikipedia:Copying within Wikipedia § Reusing deleted material. Since deleted revisions are not publicly visible, attribution is provided by a list of usernames. When such a list is a separate page, it is tagged with {{Attribution history}}, which includes it in Category:Pages used to preserve attribution.

Wikipedia:Selective deletion is a copyright cleanup technique that has been superseded by revision deletion. It involves deleting the page and restoring specific revisions, so it uses these attribution methods.

Revision deletion

When using Wikipedia:Revision deletion and deselecting the Delete editor's username or IP option, usernames are not deleted. They remain visible in the history, which still functions as a list of authors. This is the setting generally used, including with the RD1 copyright criterion.

Wikipedia:Revision deletion § Notes on use:

Username hiding (copyright attribution issues)

Wikipedia's licenses require that accessible edits be linked to the user who performed them, so it is generally a problem to hide the username from a revision while leaving their edited changes to the page in public view.

Cases where it is acceptable are:

• The revision contains no valid information copyrightable to the user who posted it (e.g. plagiarism, gibberish, vandalism, adding categories, no copyrightable change made to revision text, etc.); or
• All copyrightable changes have been reverted and the text of all intervening revisions has been hidden; or
• The user accidentally posted while being "logged out" and the aim is protection of privacy at the request of the user.

Wikipedia:Revision deletion § Changing visibility settings:

Hiding of a username or IP should only be used where that username or IP has a reason in and of itself to be hidden, such as accidentally editing logged out or an attack username. Hiding a username will remove the contribution completely from the user's contributions list (except from administrators, who will see a warning indicating it is invisible to users), rather than a crossed out entry for deleted edits without hidden username. This will cause issues with users trying to review actions taken on the user, as well as potential copyright violation risks.