check_admin_referer
check_admin_referer is an event that occurs during the run of check_admin_referer(), which helps protect the admin interface from CSF attacks. The action is only triggered if someone passes the built-in defenses. You could use this to potentially beef up the protection, if you think it is lacking.
Context:
File: wp-admin/admin-functions.php
function check_admin_referer() {
$adminurl = strtolower( get_settings('siteurl') ) . '/wp-admin';
$referer = strtolower( $_SERVER['HTTP_REFERER'] );
if ( !strstr($referer, $adminurl) )
die(__('Sorry, you need to <a href="http://codex.wordpress.org/Enable_Sending_Referrers">enable sending referrers</a> for this feature to work.'));
do_action('check_admin_referer');
}</a>
This hook provides no parameters. You use this hook by having your function echo output to the browser, or by having it perform background tasks. Your functions shouldn't return, and shouldn't take any parameters
This hook is an action which means that it primarily acts as an event trigger, instead of a content filter. This is a semantic difference, but it will help you to remember what this hook does if you use it like this: add_action('check_admin_referer', 'your_function');