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action is not described

check_ajax_referer action-hook . WP 2.1.0

Fires once the Ajax request has been validated or not.

Usage

add_action( 'check_ajax_referer', 'action_function_name_5439', 10, 2 );
function action_function_name_5439( $action, $result ){
	// action...
}
$action(string)
The Ajax nonce action.
$result(false/int)
False if the nonce is invalid, 1 if the nonce is valid and generated between
0-12 hours ago, 2 if the nonce is valid and generated between 12-24 hours ago.

Where the hook is called

check_ajax_referer()
wp-includes/pluggable.php 1153
do_action( 'check_ajax_referer', $action, $result );

Where the hook is used (in WP core)

Does not used.