WordPress at a glance
action is not described

signup_finished action-hook . WP 3.0.0

Fires when the site or user sign-up process is complete.

Usage

add_action( 'signup_finished', 'action_function_name_5192' );
function action_function_name_5192(){
	// action...
}

Where the hook is called

confirm_another_blog_signup()
confirm_user_signup()
confirm_blog_signup()
wp-signup.php 492
do_action( 'signup_finished' );
wp-signup.php 617
do_action( 'signup_finished' );
wp-signup.php 775
do_action( 'signup_finished' );

Where the hook is used (in WP core)

Does not used.