Change preferences of the current user.
Only options which are registered in core or in one of installed extensions, or options with keys prefixed with userjs- (intended to be used by user scripts), can be set.
MediaWiki:Apihelp-options-description
This website contains links to software which is either no longer maintained or will be supported only until the end of 2019 (CKFinder 2). For the latest documentation about current CKSource projects, including software like CKEditor 4/CKEditor 5, CKFinder 3, Cloud Services, Letters, Accessibility Checker, please visit the new documentation website.
If you look for an information about very old versions of CKEditor, FCKeditor and CKFinder check also the CKEditor forum, which was closed in 2015. If not, please head to StackOverflow for support.