Edit summary/edit summary
On a page being edited, a small "Summary" field is found under the main edit box. It looks like this:
It is good practice to fill in the Edit Summary field, or add to it in the case of section editing, as it helps everyone to understand what is changed, such as when perusing the history of the page. It's a good idea to set your user preferences (under Edit) to "Prompt me when entering a blank edit summary".

# Properties
The edit summary box can hold one line of 200 characters. If you attempt to type or paste more, only the first 200 characters will be displayed - the rest will be disregarded. Also, for example attempting to add 10 new characters (at the end or in between) to a summary already containing 195 characters will result in the first 5 new characters being inserted and the second 5 being disregarded.
The "Show preview" button also provides a preview of the edit summary to facilitate checking links.

# Recommendations
Always fill in the summary field. This is considered an important guideline. Even a short summary is better than no summary. An edit summary is even more important if you delete any text; otherwise, people may question your motives for the edit. Also, mentioning one change but not another one can be misleading to someone who finds the other one more important; add "and misc." to cover the other change(s).
Accurate summaries help people decide whether it is worthwhile for them to check a change. We've found that summaries often pique the interest of contributors with expertise in the area. This may not be as necessary for "minor changes", but "fixed spelling" would be nice even then.
In the case of a small addition to an article, it is highly recommended to copy the full text of this addition to the summary field, giving a maximum of information with a minimum of effort. Put ft in front, as an abbreviation of "full text" (see the Abbreviations section for other abbreviations). This way, readers of the summary will be unlikely to check the page itself as they already know the extent of the edit. These kinds of edits allow users to check Recent changes, Page history and User contributions (see below) very efficiently - this also reduces the load on the servers.
If the addition is more than 200 characters, so it does not fit fully in the edit summary box, you should write a short summary of the changes you have introduced into the article. For an addition of, say, 400 characters you can also save time by simply copying that into the summary field. The excess will fall off, and the first 200 characters will usually be acceptable as a crude "summary".
Unfortunately you can copy only one line of text from the edit box into the edit summary box. The contents of further lines can be pasted at the end of the line. Thus, for example, a bulleted "see also" list is cumbersome to put in the edit summary box. One possible workaround for a new list is putting the list on one line, separated by the asterisks for the bullets, copying it to the edit summary box, and then, in the main edit box, putting the new lines before the asterisks.
In addition to a summary of the change itself, the summary field may also contain an explanation of the change; note that if the reason for an edit is not clear, it is more likely to be reverted, especially in the case that some text is deleted. To give a longer explanation, use the Talk page and put in the edit summary "see Talk".
After saving the page, the summary can not be edited--another reason to avoid spelling errors.
In the case of important omissions or errors in the edit summary, you can make a dummy edit just to put the correction in the edit summary.

# Places where the edit summary appears
The edit summary appears in black italics in the following places:
- Page history - list of changes to the page you edited
- User contributions - list of all your edits
- Watchlist- - list of recent changes to watched pages (logged-in users only)
- diff page - shows the difference between two edits
- Recent changes - list of all recent edits
- Wikipedia IRC channels - real time list of all edits
- Related changes - list of recent changes to pages linked to the page you edited
- List of new pages: shows the edit summary of the creation.
- Use the enhanced watchlist to see all recent changes in the watched pages, not just the last change in each page.

# Abbreviations
Experienced users, especially those with many edits to make, will often use abbreviations in edit summaries (as well as log entries), in order to save time; for example, "rv" for "revert". These should be used with care, as they can be confusing for inexperienced users, but they are generally fine for small edits such as formatting and grammar changes. See Edit summary legend for a list of commonly used abbreviations in edit summaries.

# Searching
The Wikimedia search function can not search edit summaries, and they are not indexed by external search engines.

# File upload summary
When uploading an image one can supply an upload summary. This serves multiple purposes:
- as second part of the automatically created edit summary of the upload log (the first part giving the file name)
- as text in the entry of the image history
- in the case that the file name of the image is new:
as edit summary for the creation of the image page
as wikitext for the editable part of the image page, which includes the following possibilities:
briefly describe the image
provide internal or external links
call templates
specify one or more categories the image is in
- as edit summary for the creation of the image page
- as wikitext for the editable part of the image page, which includes the following possibilities:
briefly describe the image
provide internal or external links
call templates
specify one or more categories the image is in
- briefly describe the image
- provide internal or external links
- call templates
- specify one or more categories the image is in
The capacity of the upload summary is one line of 250 characters; in the upload log the last part may fall off, because this can contain 255 characters, including "uploaded "filename"".
Note that there is no preview function to check the code for the links, template calls and category tags, but of course, if needed one can edit the image page after uploading, to correct errors and also to extend the text.
See also Help:Image page.

# Section editing
When adding a new section to a discussion page with the "+" button, the section title is used as the edit summary. When editing an existing section, the section title is inserted at the beginning of the edit summary, enclosed with /- and */ marks, for example /- External links */. Details of the edit should be added after this text. In the case that you provide a long summary yourself you can delete the section title in order to stay within the limit of 200 characters.
When viewing such an edit summary, the section name will appear in grey, with a small link next to it:  External links. Clicking the link to view the section (if the section no longer exists, the link will just take you to the page).
If you create a new section before or after an existing section by clicking a section "edit" link, delete the text between /- and */ marks to avoid confusion. It is possible to manually include links to multiple sections using the /- */ syntax  this may be useful when editing several sections at once.
For example, the edit summary:
is rendered as:
Foo test Bar test

# "Post a comment" feature
When starting a new thread on a Talk page, the "Post a comment" feature can be used. Click the plus sign next to the Edit link. A box labelled "Subject/headline" appears before the main editing box. Text typed into the subject field becomes both the edit summary and a new heading (which is added to the end of the page), and text entered into the main edit box is inserted below this heading.

# Automatic summaries
In certain circumstances, an automatic summary is generated when an edit is saved without one. This is slightly different to the summary added when editing a section, as that can be modified by the user before saving.
With the exception of the automatic summary when creating a redirect, which usually says all that needs to be said, these are not a substitute for a proper edit summary  you should always leave a meaningful summary, even in the above cases. They are, however, useful in providing some context for edits made by inexperienced users who are not aware of the importance of edit summaries, and for spotting vandalism.

# Rendering of wikitext; URLs
Text in edit summaries renders internal links, including piped links, and interwiki links, even when enclosed within  and . Therefore, copying wikitext in the edit summary box may be preferable to copying text from the preview, except when one wants to save space.
Other wikitext coding is not interpreted.
When copying an external link from the preview into the edit summary box then, depending on the operating system, the 
"printable version" is copied, i.e. how it is normally rendered, and in addition, between parentheses, the URL; hence the same information as in the wikitext, but in a different format, as well as a possible sequential number.
ar:: 
cs:Wikipedie:Shrnuti editace
da:Wikipedia:Beskrivelse
de:Hilfe:Zusammenfassung und Quelle
fi:Wikipedia:Yhteenveto
id:Wikipedia:Ringkasan
is:Hjalp:Breytingar agrip
ka::
nl:Help:Samenvatting
sk:Wikipedia:Zhrnutie uprav
sl:Wikipedija:Povzetek urejanja
sv:Wikipedia:Sammanfattning
yi::