WordPress at a glance
action is not described

wpmuadminedit action-hook . WP 3.0.0

Fires just before the action handler in several Network Admin screens.

This hook fires on multiple screens in the Multisite Network Admin, including Users, Network Settings, and Site Settings.

Usage

add_action( 'wpmuadminedit', 'action_function_name_8966' );
function action_function_name_8966(){
	// action...
}

Where the hook is called

In file: /wp-admin/network/edit.php
wpmuadminedit
wp-admin/network/edit.php 26
do_action( 'wpmuadminedit' );
wp-admin/network/users.php 18
do_action( 'wpmuadminedit' );
wp-admin/network/sites.php 55
do_action( 'wpmuadminedit' );
wp-admin/network/settings.php 66
do_action( 'wpmuadminedit' );

Where the hook is used (in WP core)

Does not used.