how to use elgg_extend_view

the comment  of the function says:

 * The output of any view can be prepended or appended to any other view.
 *
 * The default action is to append a view.  If the priority is less than 500,
 * the output of the extended view will be appended to the original view.

 I don't quiet understand: Is it means:

priority>=500 : appended ?

priority<500 : prepended ?

i also want to find more info on this page : http://docs.elgg.org/Views/Extend

but there is no more explaination.

  • When you extend a view and you want to add your content above or after this view, you can do that by calling elgg_extend_view() with a third parameter which sets its priority.

    • Any number less than 500 (priority < 500) will cause your content to be added before this primary view. 
    • Any number greater or equal (priority >= 500) will cause your content to be added after this primary view.