You can use this to, for example, to link from BazBar to "FooBar/SubPage",
or from BazBar/SubPage to "FooBar/SubPage".
+
+You can also use ".." in a link, to specify exactly which page to link to,
+when there are multiple pages with similar names and the link goes to the
+wrong page by default. For example, linking from "FooBar/SubPage" to
+".../OtherPage" will link to the "OtherPage" in the root of the wiki, even
+if there is a "FooBar/OtherPage".