User:Minimac/Sandbox

All pages that can be changed on Wikipedia has a page history which can be found by clicking the "history" tab at the top of the page. The page history has a list of the page's previous revisions. The revisions include the date and time (in UTC) of each change, the name or IP address of the user who made it, and the summary of the change.

Using a history page

On a history page:

• All past changes to the page are listed in reverse-chronological order (In other words the newest change is seen at the top).
• To view a version, click a date.
• To compare an old version with the newest, click cur.
• To compare a version with an older one, click last.
• To compare two specific versions, click the circles (in both columns) next to them. Then click the Compare button to see the differences between them.
• Small changes are shown as m.

It is possible to bring up an old version of a page by following the link to that version, clicking "change" and then saving. But be careful when doing this, because all the newest changes will be lost.

Moved and deleted pages

When a page is moved (renamed), the entire edit history of the article, before and after the move, is shown. The old title becomes a redirect and loses its edit history.

If instead of a move, the entire content was cut and pasted into a new substitute article, the page history gets spread across two articles. The histories can be merged in this case.

When two pages are merged, typically one becomes a redirect. In this case the revision history of the redirect is kept.

When a page is deleted, its revision history remains in the database and can be retrieved by an administrator, who can also undelete the page (see Wikipedia:Viewing and restoring deleted pages).

Administrators can also remove selected revisions from a page history, for example if they contain defamatory text. For details, see Selective deletion.

Images

An "image" (in the broad sense of an uploaded file) can be edited, or, more generally, be replaced by a different image, by uploading a new image file with the same name. Again all versions are kept. The image history listing forms part of the image description page, which appears when clicking on the image. The image history consists of this and the old versions themselves.

Images which have been deleted from their source are not available (not to be confused with images removed from an article but not from their source), the only record available is the upload log, deletion log and possibly the "votes for deletion" archive. Neither the latest nor older versions are kept by the system, hence it is not possible to restore a deleted image without uploading it again.

Linking to a specific version of a page

It is sometimes useful to link to a specific version of an article (a snapshot of it). For example, one might have done a review of a Wikipedia article and want to indicate which particular version was reviewed.

If the version is not the current version, one can use the page history to view the old version of the page. The URL of this old version is suitable for use to permanently reference this version, and can usually be obtained from the browser's location bar. See also URLs of Wikipedia pages.

However if a page contains transcluded text (such as a template), or a time-based variable (such as CURRENTTIME), it will be rendered according to the current state of the template or the time now, possibly producing a different result than was rendered at the time the old version was saved. (One way to produce a representation of the current version of a page which will not be affected by changes to templates is to copy the wikitext to a user page and use "subst:", if necessary recursively.)

Searching and exporting histories

The history page contains a link "Revision history search". This links to Wikiblame, a tool for searching the entire history of a given page.

Another useful tool is the Special:Export page, which is used to produce an XML file with the wikitext of the current and (optionally) all old versions of one or more specified pages, with date, time, user name, and edit summary. How the XML file is displayed depends on the browser (it can also be saved locally for later searching and analysis). For more information on this feature, see Help:Export.

The following may also be useful:

• http://tools.wikimedia.de/~daniel/WikiSense/Contributors.php – a tool to sort the page history by editor and count the number of edits for each editor (works for most Wikimedia sites; can also be downloaded for adaptation to other MediaWiki sites).
• Wikipedia:Usemod article histories – information on retrieving page histories from before January 2002.

Web feeds

Web feeds (RSS and Atom) for the history of a page are obtained by assigning to "feed" (one of the Template:Mlmw) the value "rss" or "atom", i.e., by adding "&feed=rss" or "&feed=atom" to the URL of the history page. This gives the {{#invoke:Help:diff|diffs}} of the last 10 edits, each with a link to the ordinary, full diff page. Depending on the browser there may be possibilities such as sorting by author.

Archiving

Archiving talk page text in separate pages is superior to using the page history as sole archive:

• "What links here" works for archive pages, but not for old revisions.
• Texts in archive pages can be found by search engines. For content which is only in a revision history the possibilities are limited. (However, for a popular site like the English Wikipedia there are a few tens of mirror sites; how recent the copies are varies, so searching for some specific old content search engines may find it on some of them.) Page histories can only be searched after applying Special:Export.
• Archive pages can be organized and titled afterwards in a suitable way, while e.g. edit summaries cannot be supplied afterwards. However, an index of old versions of a page, with links to them, could be prepared.

Copyright status

Wikipedia does not give legal advice.

The Wikimedia Foundation wishes to make users of historical versions of articles aware that some of the history may be problematic and not necessarily reliable.

Title 17 United States Code § 108 archive notice: page histories should be considered not-for-profit archival material. Although all contributions are supposed to be compatible with CC-By-SA, it is possible that a user has inserted something which is a violation of copyright, in which case the user had no right to release it as CC-By-SA. In these cases, Wikipedia does not have a general policy of always deleting all copyright problems from the history, particularly if the edit is made to an existing article rather than a new one, although such material will be removed from the current version of a page. In the event of a DMCA takedown notice, the Wikimedia Foundation may remove violating versions from the page history. In other cases, the version may be kept to allow proper tracking of authors and demonstrate compliance with all legal requirements. You are being given notice under Title 17 that you are responsible for complying with copyright laws in regards to archival material, and that not all versions in a page history are necessarily available under the CC-By-SA.

As noted at the end of each history revision, in the text at MediaWiki:history copyright, the page histories may contain material that is subject to copyright limitations. While we attempt to remove such material from the current version (see copyright problems) it is kept in the history for research and author attribution purposes. As Wikimedia is a not-for-profit company, this is believed to be fair use.

See also Wikipedia talk:Copyright violations on history pages for further discussion of this point.

History tab History