This page is the summary of much discussion on policy talk pages. It is not a guideline, but rather an effort to clarify the definition of the words published and accessible as used on guideline and policy pages.
All reliable sources must be both published and accessible to at least some people, according to definitions in the relevant policies and guidelines. Sources that are not published (e.g., something someone said to you personally) or not accessible (e.g., the only remaining copy of the book is locked in a vault, with no one allowed to read it) are never acceptable as sources on Wikipedia.
Below are presented separate definitions of published and accessible for Wikipedians. These are separate from the idea of "reliable", which is covered elsewhere. Please note, this definition is not identical with the Wikipedia or Wiktionary pages about publications, because it is the specific application of these concepts to the English Wikipedia.
The word published derives from the Latin word meaning to make known publicly. Publication is the first threshold that all information must meet to be included in Wikipedia's articles. For Wikipedia's purposes, published means any source that was "made available to the public in some form".
The term published is most commonly associated with text materials, either in traditional printed format or online. However, audio, video, and multimedia materials that have been recorded then broadcast, distributed, or archived may also meet the necessary criteria to be considered a reliable source. Like text sources, media sources must be normally produced by a third party and be properly cited, although self-published sources are also considered "published" for Wikipedia's purposes and can sometimes be used in articles. Additionally, an archived copy of the media must exist and be available to the general public. It is useful but by no means necessary for the archived copy to be accessible via the Internet. The definition also encompasses material such as documents in publicly accessible archives, inscriptions on monuments, gravestones, etc., that are available for anyone to see.
It is necessary for the information to be made available to the public in general, not just to individual editors or selected groups of people. For example, if you request a copy of an unpublished book, and the author sends you a copy, the book is still considered unpublished. The book remains unpublished even if the author offers to supply copies to other Wikipedians. To be considered published, the book must be distributed to the public in general, not to individuals.
Each of the items listed under "examples" below must have been actually distributed to a public. An item that was never distributed to a public, is not considered "published" by the Wikipedian definition.
Your memory of source information is not published: you must have the source in your possession to cite the information correctly.
Even if the publication is retracted afterwards (unless due to copyright reasons), it should be considered published for Wikipedia's purposes. A published translation of unpublished work by another person is also considered publication for Wikipedia's purposes.
- A book distributed to a public (e.g., sold in a bookstore);
- A newspaper, magazine, journal, pamphlet or flyer distributed to a public;
- A film, video, CD, or DVD distributed to theatres or video stores; a radio program including its contents actually broadcast; a television program; a streaming video or audio source on the Internet; a song recording distributed to a public;
- A transcript or recording of a live event, including: plays, television broadcasts, documentaries, court trials, speeches or lectures, demonstrations, panel discussions, or meetings, a song sheet;
- A webpage on the Internet, including public web forums,
- A sign, billboard or poster displayed in a public location;
- A computer program;
- A broadcast email, including email-lists if they are archived and public—but not email messages or other forms of personal communication sent only to you or a small number of people
A source is considered accessible if it is available to the public to review in some manner.
The idea behind requiring a source to be 'accessible' is to allow a third-party, unaffiliated, person to review and scrutinize the source. This is a requirement of Wikipedia's verifiability policy. The third party is someone who is unaffiliated with the editor, publisher, group or institution in control of the source, or primary source of the information or expression (such as art). This third party must have some possibility of being able to verify that the source exists and contains the information purported.
However, the mere fact that an item is no longer available online, without cost, or in a retail store is insufficient to nullify its status as accessible. If the item is available online or at a library, it is still considered accessible.
- An item that is available, in at least one public library, anywhere in the world, is considered accessible.
- A book that can be bought in at least one store, anywhere in the world, including a used bookstore, is accessible.
- A live event that was neither recorded nor transcribed is not accessible.
- A web list or forum must be both public and archived in a public location to be considered accessible.
- A radio or television program that is archived by the broadcaster is "accessible" if the broadcaster allows people to visit the studio and listen to the program (perhaps for a fee); it is not accessible if the general public is not allowed to listen to the program.
- Any item that cannot be reviewed, due to zero copies being available to the public at this time (even if copies were available to the public once upon a time) is not accessible.
- Wikipedia:Reliable sources/Cost: A publication need not be free, online, or convenient for you
- Wikipedia:Potentially unreliable sources#Personal communication
- Wikipedia:Verifiable, not verified