woocommerce_rate_code │ filter-hook │ WC 1.0

Usage

add_filter( 'woocommerce_rate_code', 'wp_kama_woocommerce_rate_code_filter', 10, 2 );

/**
 * Function for `woocommerce_rate_code` filter-hook.
 * 
 * @param  $code_string 
 * @param  $key         
 *
 * @return 
 */
function wp_kama_woocommerce_rate_code_filter( $code_string, $key ){

	// filter...
	return $code_string;
}

$code_string

-

$key

-

Where the hook is called

return apply_filters( 'woocommerce_rate_code', $code_string, $key );

Where the hook is used in WooCommerce