Manual:$wgBreakFrames

Site customization: $wgBreakFrames
Break out of framesets. This can be used to prevent external sites from framing your site with ads.
Introduced in version:	1.9.0 (r18220)
Removed in version:	still in use
Allowed values:	(boolean)
Default value:	false

Other settings: Alphabetical | By Function

Details

Break out of framesets. This can be used to prevent external sites from framing your site. If set to "true" it will also prevent positive uses of frames.

Note, since MediaWiki 1.16.1, certain pages (like edit pages) automatically have frames broken by default to prevent click jacking attacks.

See also

• Manual:$wgEditPageFrameOptions