WordPress at a glance
action is not described

wp_print_scripts action-hook . WP 1.0

This action is documented in wp-includes/functions.wp-scripts.php

Usage

add_action( 'wp_print_scripts', 'action_function_name_2400' );
function action_function_name_2400(){
	// action...
}

Where the hook is called

print_head_scripts()
wp_print_scripts
wp_print_head_scripts()
wp_print_scripts
wp_print_scripts()
wp_print_scripts
wp-includes/script-loader.php 1837
do_action( 'wp_print_scripts' );
wp-includes/script-loader.php 1955
do_action( 'wp_print_scripts' );
wp-includes/functions.wp-scripts.php 95
do_action( 'wp_print_scripts' );

Where in WP core the hook is used WordPress

wp-includes/script-loader.php 523
add_filter( 'wp_print_scripts', 'wp_just_in_time_script_localization' );