WordPress at a glance
action is not described

admin_footer-(hook_suffix) action-hook . WP 2.8.0

Prints scripts or data after the default footer scripts.

The dynamic portion of the hook name, $hook_suffix, refers to the global hook suffix of the current page.

Usage

add_action( 'admin_footer-(hook_suffix)', 'action_function_name_1122' );
function action_function_name_1122(){
	// action...
}

Where the hook is called

In file: /wp-admin/admin-footer.php
admin_footer-(hook_suffix)
wp-admin/admin-footer.php 99
do_action( "admin_footer-{$hook_suffix}" );

Where the hook is used (in WP core)

wp-includes/widgets/class-wp-widget-media.php 114
add_action( 'admin_footer-widgets.php', array( $this, 'render_control_template_scripts' ) );
wp-includes/widgets/class-wp-widget-text.php 68
add_action( 'admin_footer-widgets.php', array( 'WP_Widget_Text', 'render_control_template_scripts' ) );
wp-includes/widgets/class-wp-widget-custom-html.php 77
add_action( 'admin_footer-widgets.php', array( 'WP_Widget_Custom_HTML', 'render_control_template_scripts' ) );