woocommerce_proceed_to_checkout action-hook . WC 1.0

Usage

add_action( 'woocommerce_proceed_to_checkout', 'action_function_name_6099' );
function action_function_name_6099(){
	// action...
}

Where the hook is called

<?php do_action( 'woocommerce_proceed_to_checkout' ); ?>

Where in WP core the hook is used WooCommerce

add_action( 'woocommerce_proceed_to_checkout', 'wc_get_pay_buttons', 10 );

add_action( 'woocommerce_proceed_to_checkout', 'woocommerce_button_proceed_to_checkout', 20 );