Select a presentation style that is optimized for humans or for implementors. In a modern browser, you may select between presentation styles through the browser's user interface.
This section is normative.
Frequently, it is useful for an author of MonkeyML to allow the user to shift focus from one branch of the DOM tree to another.
When the 'brachiate()' method is invoked, a User Agent must change the branch of the tree that is in focus; if a parameter is provided which matches a known branch, a User Agent must change the focus to that branch, and if the provided parameter does not match a known branch, the User Agent may change the focus to the next sibling branch in the document order, or may change the focus to the parent branch. If no parameter is provided, a User Agent must raise a 'FALL' exception and must not change the branch focus.