Common.js and Common.css are pages which influence the interface and layout of Wikipedia.
Common.js may refer to one of several JavaScript pages:
Wikipedia's sitewide "common JavaScript" page, located at MediaWiki:Common.js. This is loaded for all users.
An individual user's "common JavaScript" page, located at Special:MyPage/common.js. Unlike Special:MyPage/skin.js, which redirects to the JavaScript page of the user's current skin, a user's common.js page is loaded regardless of which skin they are using.
Wikipedia's sitewide "common CSS" page, located at MediaWiki:Common.css. This is loaded for all users.
An individual user's "common CSS" page, located at Special:MyPage/common.css. Unlike Special:MyPage/skin.css, which redirects to the CSS page of the user's current skin, a user's common.css page is loaded regardless of which skin they are using.
See alsoedit
the MediaWiki interface manual, especially the subpages on JavaScript and Stylesheets
Explanation how a user can customize the skin with these pages
Overview of these and related pages
Use of CSS
v
t
e
Wikipedia technical help
Get personal technical help at the Teahouse, help desk, village pump (technical), talk pages or IRC.