WordPress at a glance
action is not described

admin_print_scripts action-hook . WP 1.0

This action is documented in wp-admin/admin-header.php

Usage

add_action( 'admin_print_scripts', 'action_function_name_7022' );
function action_function_name_7022(){
	// action...
}

Where the hook is called

WP_Customize_Widgets::print_scripts()
admin_print_scripts
iframe_header()
admin_print_scripts
wp_iframe()
admin_print_scripts
wp-includes/class-wp-customize-widgets.php 661
do_action( 'admin_print_scripts' );
wp-admin/includes/template.php 2052
do_action( 'admin_print_scripts' );
wp-admin/includes/media.php 560
do_action( 'admin_print_scripts' );
wp-admin/admin-header.php 130
do_action( 'admin_print_scripts' );

Where in WP core the hook is used WordPress

wp-includes/class-wp-customize-widgets.php 33
remove_action( 'admin_print_scripts', 'print_emoji_detection_script' );
wp-includes/class-wp-customize-widgets.php 354
add_action( 'admin_print_scripts', 'print_emoji_detection_script' );
wp-includes/class-wp-customize-widgets.php 355
add_action( 'admin_print_scripts', 'print_head_scripts', 20 );