To link to or from a [[SubPage]], you can normally use a regular [[WikiLink]] that does not contain the name of the parent directory of the [[SubPage]]. Ikiwiki descends the directory hierarchy looking for a page that matches your link. For example, if FooBar/SubPage links to "OtherPage", ikiwiki will first prefer pointing the link to FooBar/SubPage/OtherPage if it exists, next to FooBar/OtherPage and finally to OtherPage in the root of the wiki. Note that this means that if a link on FooBar/SomePage to "OtherPage" currently links to OtherPage, in the root of the wiki, and FooBar/OtherPage is created, the link will _change_ to point to FooBar/OtherPage. On the other hand, a link from BazBar to "OtherPage" would be unchanged by this creation of a [[SubPage]] of FooBar. You can also specify a link that contains a directory name, like "FooBar/OtherPage" to more exactly specify what page to link to. This is the only way to link to an unrelated [[SubPage]]. You can use this to, for example, to link from BazBar to "FooBar/SubPage", or from BazBar/SubPage to "FooBar/SubPage".