H:EDIT
Wikipedia is a wiki, meaning anyone can edit nearly any page and improve articles immediately. You do not need to register to do this, and anyone who has edited is known as a Wikipedian or editor. Small edits add up, and every editor can be proud to have made Wikipedia better for all. There are two editing interfaces: the new VisualEditor (VE) and classic wikitext editing (wiki markup), which uses the Source Editor.

Editing articles

Content style and policies 

An encyclopedic style with a formal tone is important: straightforward, just-the-facts, instead of essay-like, argumentative, or opinionated. The goal of a Wikipedia article is to create a comprehensive and neutrally written summary of existing mainstream knowledge about a topic. Wikipedia does not publish original research. An encyclopedia is, by its nature, a tertiary source that provides a survey of information already published in the wider world. Ideally, all information should be cited and verifiable by reliable sources. Sourcing requirements are significantly stricter in articles on living persons.

Edit screen(s) 
Editing most Wikipedia pages is simple. Wikipedia uses two interface methods: classic editing with the Source Editor through wikitext (wiki markup), and a new VisualEditor (VE). 

Wikitext editing using the Source Editor is chosen by clicking the Edit source tab at the top of a Wikipedia page (or on a section-edit link). This opens an editable copy of the page, showing all the wikitext used there, and the Source Editor toolbar offers simple menu options to add or change the formatting. Wikitext is used extensively throughout Wikipedia for such things as hyperlinks, tables and columns, footnotes, inline citation, special characters and so on. The Source Editor lets users toggle on 'wikitext highlighting' which uses different colours to help differentiate article text from wikitext.

The VisualEditor option is intended as a user-friendly, "What You See Is What You Get" (WYSIWYG) editing aid, allowing one to edit pages without the need to learn wikitext markup. It is available only to registered, logged-in users through an opt-in choice available through personal preferences. See the VisualEditor user guide for more information.

The Wikipedia community has developed style guidelines to make articles and facts appear in a standardized form, and Wikipedia easier to use as a whole. A basic list of wikitext can be found on the cheatsheet. An "edit toolbar" is provided just above the edit box (pictured below), which allows logged-in users (by selecting the option in personal preferences) to automatically place and format various aspects of wiki code. See Help:Wikitext for more information, remember that you can't break Wikipedia, and, although there are many protocols, perfection is not required, as Wikipedia is a work in progress.

When you have finished editing, you should write a short edit summary in the small field below the edit box (pictured below). You may use shorthand to describe your changes, as described in the legend. To see how the page looks with your edits, press the "Show preview" button. To see the differences between the page with your edits and the previous version of the page, press the "Show changes" button. If you're satisfied with what you see, be bold and press the "Publish changes" button. Your changes will immediately be visible to all Wikipedia users.

Note: Do not sign the edit summary line with your ~~~~ signature, as it does not work there.

Minor edits 

A check to the "minor edit" box signifies that only superficial differences exist between the version with your edit and the previous version: typo/grammar corrections, formatting and presentational changes, rearranging of text without modifying content, etc. A minor edit is a version that the editor believes requires no review and could never be the subject of a dispute. The "minor edit" option is one of several options available only to registered users. Editors should not feel that marking a change as minor devalues their effort to edit.

Major edits 

All editors are encouraged to be bold and strong, but there are several things that a user can do to ensure that major edits are performed smoothly. Before engaging in a major edit, a user should consider discussing proposed changes on the article discussion/talk page. During the edit, if doing so over an extended period, the  tag can reduce the likelihood of an edit conflict. Once the edit has been completed, the inclusion of an edit summary will assist in documenting the changes. These steps will help all to ensure that major edits are well received by the Wikipedia community.

A major edit should be reviewed to confirm that it is consensual to all concerned editors. Therefore, any change that affects the meaning of an article is major (not minor), even if the edit is a single word.

There are no necessary terms to which you have to agree when doing major edits, but the preceding recommendations have become best practice. If you do it your own way, the likelihood of your edits being reedited may be higher.

When performing a large edit, it is suggested that you periodically, and before pressing "Publish changes", copy your edits into an external text editor (preferably one without formatting, such as Windows Notepad). This ensures that in the case of a browser crash, you will not lose your work. If you are adding substantial amounts of work, it is also a good idea to publish changes in stages.

Adding references 

Generally, sources are added directly after the facts they support at the end of the sentence and after any punctuation. Wikipedia permits editors to use any citation system that allows the reader to understand where the information came from and strongly encourages the use of inline citations to do so. Common methods of placing inline citations include footnotes, shortened footnotes and parenthetical references.

Inline citations are most commonly placed by inserting a reference between <ref> ... </ref> tags, directly in the text of an article. The reference is a footnote, appearing as an inline link (e.g. [1][2]) to a particular item in a collated, numbered list of footnotes, found wherever a  template or <references /> tag is present, usually in a section titled "References" or "Notes". If you are creating a new page or adding references to a page that didn't previously have any, don't forget to add a references section with this display markup.

There are a number of tools available to help with citation placement and formatting, some of which are internal tools and scripts, while others are available from external sites. For an example of the former, RefToolbar is a JavaScript toolbar displayed above the edit box that provides the ability to automatically fill out various citation templates and insert them in the text already formatted inside <ref> ... </ref> tags. For an example of the latter, the Wikipedia DOI and Google Books Citation Maker  converts a digital object identifier (DOI) or Google Books address (URL) into a filled-out  or  template ready to be pasted into an article. See Help:Citation tools for many others.

Adding images, sounds, and videos 

A file that is already hosted on Wikipedia or the Wikimedia Commons can be inserted with the basic code [[File:FILENAME|thumb|DESCRIPTION]]. (Image: can be substituted for File: with no change in effect; the choice between the two is purely a matter of editorial preference.) Using thumb generates a thumbnail of an image (the most common placement option), which is typically sized differently from the original image. The Wikimedia Commons' File Upload Wizard and Wikipedia's File Upload Wizard will guide you through the process of submitting media. There are various file formats available.

Article creation 

Before starting a new article, please understand Wikipedia's notability requirements. In short, the topic of an article must have already been the subject of publication in reliable sources, such as books published by major publishing houses, newspapers, magazines, peer-reviewed scholarly journals and websites that meet the same requirements as reputable print-based sources. Information on Wikipedia must be verifiable; if no reliable third-party sources can be found on a topic, then it should not have a separate article. Wikipedia's concept of notability applies this basic standard to avoid indiscriminate inclusion of topics.

An Article Wizard is available to help you create articles — it is not required but will help you construct better articles. Note: The ability to create articles directly in mainspace is restricted to autoconfirmed users, though non-confirmed users and non-registered users can submit a proposed article through the Articles for Creation process, where it will be reviewed and considered for publication. Before creating an article, please search Wikipedia first to make sure that an article does not already exist on the subject, and please also review the article titling policy for guidance on what to name the article.

Talk pages 

Every article on Wikipedia has a talk page, reached by clicking the "Talk" tab just above the title (for example, Talk:Alexander the Great). There, editors can discuss improvements to the content of an article. If you ever make a change that gets reverted by another editor, discuss the change on the talk page! The BOLD, revert, discuss cycle is a popular method of reaching consensus. It is very important that you conduct yourself with civility and assume good faith on the part of others. Edit warring (repeatedly overriding or reimplementing contributions) is highly discouraged.

Most other types of pages on Wikipedia also have associated talk pages, including the User page each editor is assigned once they sign up. When other editors need to contact you, they will usually do this by leaving a message on your talk page. When someone has left you a message that way, you will see a notice the next time you log in or view a page on Wikipedia.

Sign your contributions to a Talk page by using four tildes (~~~~), which produces your username and a time/date stamp.

Protected pages and source code 

Some pages are protected from editing. These pages have a "View source" tab instead of an "Edit" tab. You can still edit these pages indirectly by submitting an edit request—an editor with the permission to edit the protected page will respond to it.

To submit an edit request, click on the protected page's "View source" tab and then the "Submit an edit request" link at the bottom right.

Policies and conventions 

Policies, guidelines, and formatting norms are developed by the community to describe the best practices, to clarify principles, resolve conflicts, and otherwise further our goals. Make sure that you submit information that is relevant to Wikipedia's specific purpose, or your content might be deleted. You can always use the talk pages to ask questions or check to see if your idea will be accepted. Please make note of which license will cover your contributions.

See also 

Helpful tips
 Wikipedia: The Missing Manual—Editing for the first time
 Wikipedia:Article size#If you have problems editing a long article
Smartphone editing (User essay): a Wikipedia administrator's personal experiences and advice about phone editing
Naming and moving
 Wikipedia:Article titles
 Moving a page to a new name
 Wikipedia:Namespace
Style and layout
 Wikipedia:Annotated article
 Wikipedia:Layout
 Wikipedia:Manual of Style
Tools
 Draft:Sandbox
 Help:Text editor support
 Wikipedia:Tools

Related
 Wikipedia:WikiProject: if you are writing an article about something that belongs to a group of topics, check here first!
 Wikimedia Bookshelf: learning materials, videos, and handouts
 Wikipedia:Glossary: a glossary for Wikipedia editors

Notes 

Editing, Help
Editing, Help