WordPress at a glance
action is not described

network_admin_edit_(action) action-hook . WP 3.1.0

Fires the requested handler action.

The dynamic portion of the hook name, $_GET['action'], refers to the name of the requested action.

Usage

add_action( 'network_admin_edit_(action)', 'action_function_name_5980' );
function action_function_name_5980(){
	// action...
}

Where the hook is called

In file: /wp-admin/network/edit.php
network_admin_edit_(action)
wp-admin/network/edit.php 36
do_action( 'network_admin_edit_' . $_GET['action'] );

Where the hook is used (in WP core)

Does not used.