5.13 @url, @uref{url[, text][, replacement]}

@url produces a reference to a uniform resource locator (URL). It takes one mandatory argument, the URL, and two optional arguments which control the text that is displayed. In HTML and PDF output, @url produces a link you can follow. (To merely indicate a URL without creating a link people can follow, use @indicateurl, see @indicateurl{uniform-resource-locator}.)

@uref is a synonym for @url. (Originally, @url had the meaning of @indicateurl and @uref was required to produce a working link, but in practice @url was almost always misused. So we’ve changed the meaning.)

The second argument, if specified, is the text to display (the default is the URL itself); in output formats other than HTML, the URL is output in addition to this text.

The third argument, if specified, is the text to display, but in this case the URL is not output in any format. This is useful when the text is already sufficiently referential, as in a man page. Also, if the third argument is given, the second argument is ignored.