When developing your app, sometimes it is needed for fig to let other libraries/parts of the code manage the DOM inside your app. For this reason, fig provides a +skip mixin, which as the name suggests, forces fig to ignore that part of the DOM tree after initial render. The editor you see on this website uses this functionality to let CodeMirror function properly.
Let's see an example!
If you open your developer console (F12 in most browsers), you should see an element being logged. Skipped elements are attached to the app instance's .ref property, with their names being determined by the variable passed to the skip mixin. For more complex usage, see the code editor's source code.