Editing OK (section)

==Computers==
[[File:Notepad Font selection.png|thumb|right|Example of OK and Cancel buttons in Windows Notepad]]
[[File:Msxbasic.png|thumb|The [[command prompt]] for user input in [[MSX BASIC]] was {{samp|Ok}}|alt=A blue screen with white text: "MSX BASIC version 3.0 / Copyright 1988 by Microsoft / 23414 Bytes free / Disk BASIC version 1.0 / Ok" and a square representing the cursor. On the bottom line, "color auto goto list run".]]

''OK'' is used to label [[Button (computing)|buttons]] in [[Dialog Box#Application modal|modal dialog boxes]] such as [[error message]]s or print dialogs, indicating that the user can press the button to accept the contents of the dialog box and continue. When the dialog box contains only one button, it is almost always labeled ''OK''. When there are two buttons, they are most commonly labeled ''OK'' and ''Cancel''. ''OK'' is commonly rendered in [[upper case]] and without punctuation: ''OK'', rather than ''O.K. or'' ''Okay.''  The ''OK'' button can probably be traced to user interface research done for the [[Apple Lisa]].<ref>{{cite web|url=http://www.folklore.org/StoryView.py?project=Macintosh&story=Do_It.txt&topic=Lisa |title=Apple user interface designers pick ''OK'' |publisher=Folklore.org |date=17 July 1980 |access-date=12 June 2011}}</ref>

The [[Forth (programming language)|Forth]] programming language prints ''ok'' when ready to accept input from the keyboard. This prompt is used on [[Sun Microsystems|Sun]], [[Apple Inc.|Apple]], and other computers with the Forth-based [[Open Firmware|Open Firmware (OpenBoot)]]. The appearance of ''ok'' in inappropriate contexts is the subject of some humor.<ref>
{{cite conference
 |conference=[LISA '99] |title=The C Days of Y2K
 |url=http://www.usenix.org/publications/library/proceedings/lisa99/y2k.html
 |publisher=[[USENIX]]
 |date=23 November 1999
 |access-date=21 February 2011
}}</ref>

In the [[Hypertext Transfer Protocol]] (HTTP), upon which the World Wide Web is based, a successful response from the server is defined as ''OK'' (with the numerical code [[HTTP 200|200]] as specified in RFC 2616).  The [[Session Initiation Protocol]] also defines a response, ''200 OK'', which conveys success for most requests (RFC 3261).

Some [[Linux distribution]]s, including those based on [[Red Hat Linux]], display [[Booting|boot progress]] on successive lines on-screen, which include ''[&nbsp;OK&nbsp;]''.

===In Unicode===
Several [[Unicode character]]s are related to visual renderings of OK:
* {{unichar|1F197|SQUARED OK}}
* {{unichar|1F44C|OK HAND SIGN}}
* {{unichar|1F44D|THUMBS UP SIGN}}
* {{unichar|1f592|REVERSED THUMBS UP SIGN}}
* {{unichar|1F646|FACE WITH OK GESTURE}}