FitNesse. UserGuide.
MarkupCrossReference [add child]
You can add a Cross Reference to another page with the !see statement.

Markup Text
Displayed as
!see .FrontPage See: .FrontPage

Aside from being a nice syntax for cross references, this widget is also used in test suites. If a test suite page refers to test pages with !see statements, then when the suite is executed, the cross referenced tests will be added to the suite. If a test page has a !see markup, it is ignored completely even if the page is part of a suite or sub-suite.

The path to the referenced page may be an absolute or a relative path.