A piped link in MediaWiki is the usage of the "pipe" character, also known as a vertical bar, to cause a link to display one text, but go to another. For example, the following piped link appears to go to Jimmy Wales but infact actually goes to the main page: Jimmy Wales. In the source editor, this is done by creating a link like normal, but before the "]]" text, adding a pipe character ("|"), and the text you want it to display, like so: [[Jimmy Wales|Main Page]]. In the visual editor, this is done by creating a link like normal with the chain button, but, once the link has been created, pressing the "Change label" button on the pop-up and entering what you want the link to display (the target of the link was set before).
Piped links may be used for some of the following purposes:
[[Mercury_(element)|Mercury]], which allows it to the mercury element page, instead of the Mercury disambiguation page, but without the drawback of the text saying "The boiler room contained Mercury (element)".[[Atlantic_Ocean#Gulf_Stream|Gulf Stream]]