WordPress at a glance
action is not described

wp_print_scripts action-hook . WP 2.1.0

Fires before scripts in the $handles queue are printed.

Usage

add_action( 'wp_print_scripts', 'action_function_name_8772' );
function action_function_name_8772(){
	// action...
}

Where the hook is called

wp_print_scripts()
print_head_scripts()
wp_print_head_scripts()
wp-includes/functions.wp-scripts.php 72
do_action( 'wp_print_scripts' );
wp-includes/script-loader.php 2072
do_action( 'wp_print_scripts' );
wp-includes/script-loader.php 2182
do_action( 'wp_print_scripts' );

Where the hook is used (in WP core)

wp-includes/default-filters.php 488
add_filter( 'wp_print_scripts', 'wp_just_in_time_script_localization' );