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A page history shows the order in which changes were made to any editable Wikipedia page, the difference between any two versions, and a menu of special external tools. A page history is sometimes called revision history or edit history.
You can view a page's history by clicking the "View history" tab at the top of the associated page (pictured right).
The page history contains a list of the page's previous revisions, including the date and time—in UTC by default—of each edit, the username or IP address of the user who made the change, and an optional edit summary that briefly describes or explains the change. For example, the page history for this help page shows that it was first created on September 20, 2004, and that it has been changed more than 500 times during the last ten years.
On a history page:
Below is a detailed example of a page history using the default skin:
Edits are shown from newest to oldest. Each edit takes up one line which shows; time & date, the contributor's username or IP address and the edit summary, as well as other diagnostic information. Let's look at some of the functions of this page:
deletedhistoryuser right. It displays RevisionDeleted edits.
Not shown in this example: some edits may be automatically tagged by the abuse filter (example:
(Tag: references removed)); any tags applied appear after the edit summary. Tags cannot be added or removed manually, and are intended to help editors identify potential problem edits for examination; they do not prove that an edit is problematic.
Also not shown in this example: you can thank a user for their edit by clicking the Thank button. see Wikipedia:Notifications/Thanks.
It is possible to restore an old version of a page by following the link to that version, clicking "edit" and then saving. This should be done with caution, as it means that all changes made to the page since the time of that version will be undone.
In rare cases, all or part of a page history entry may be shown in grey, struck out by a horizontal line. This indicates that information has been hidden from public view by an administrator. See Revision deletion and Oversight for more on this.
The history page contains a link "Find addition/removal". 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:
Some page histories (such as User talk:Jimbo Wales) are very long, so that paging back even 500 results at a time cannot practically reach a date from several years ago. It is possible to simply change the date (YYYYMMDD) in the URL in these cases (
http://en.wikipedia.org/w/index.php?title=User_talk:Jimbo_Wales&offset=20061215142129&action=history, for example) to get a listing of results going back from that date.
A link to an Atom web feed for the history of a page is available from the lefthand
Toolbox. This gives the 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.
An RSS version of the feed can be obtained by assigning to "feed" (one of the parameters to index.php available for a history page) the value "rss", i.e., by replacing "&feed=atom" with "&feed=rss" in the Atom feed link.
To view a history of only moves and no other edits, go to special:log/move and input the name of the article in the "target" field.
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.
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 to non-administrators (not to be confused with images removed from an article but not from their source), so the only record available is the upload log, deletion log and possibly the "votes for deletion" archive. Only administrators can restore a deleted image without uploading it again.
It is sometimes useful to link to a specific version of an article - this is called a "permanent link". For example, one might have done a review of a Wikipedia article and want to indicate which particular version was reviewed.
A permanent link to the current version of an article is normally available from the sidebar, under Toolbox -> Permanent link. For other namespaces, or if the version to be linked to is not the current version, use the page's History tab to navigate to the specific version required. The URL here will be 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.) To make a permalink for use within the English Wikipedia, use Template:Oldid2.
A permalink does not necessarily reproduce the historical version of the page as it originally appeared. This is because images, templates (transcluded text and images), and time-based variables (such as CURRENTTIME) may have changed in the interim; they appear in their current state, not their historical state. Only the on-page text of the article (the wikitext that one sees when clicking 'Edit') is preserved perfectly.
It is possible to capture a visual snapshot of the current version of a page by making a web mirror: Copy the HTML file of the page, along with any auxiliary files, such as Cascading Style Sheets and image files. Help:Downloading pages lists other ways to preserve a page.
Those wishing to make use of historical versions of articles should be aware that some of the history may be problematic.
As noted at the end of each history revision, in the text at MediaWiki:history copyright, the page histories may contain material that is incompatible with our license. Although all contributions are supposed to be compatible with CC BY-SA (except limited, clearly marked fair use material in accordance with our non-free content policy), it is possible that a user has inserted something to which they did not have rights to license or which exceeds fair use. The Wikipedia volunteer community has a general policy of removing such copyright problems from publication when they are discovered (see copyright problems), but does not have a general policy of always deleting all such material from the history, particularly if the edit is made to an existing article rather than a new one. 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. As the Wikimedia Foundation is a not-for-profit company, the volunteer community believes this to be fair use. However, not all versions in a page history are necessarily available under the CC BY-SA.
Find addition/removal(Wikiblame, allows you to find the person who wrote or deleted a given passage of text),
Find edits by user(find all the edits a particular user made to the page),
Page statistics(lists all people who have edited the page, from most contributions made to least; a graph of when edits were made; and other statistics.),
Pageviews(shows a graph of how many people accessed the page over time and reports how many people have the page on their watchlist),
Fix dead links(offers tools to analyze web pages and fix links).
|This page is referenced in the Wikipedia Glossary.|