/** * WooCommerce woocommerce_order_item_line_item_html action hook registeration. */ add_action('woocommerce_order_item_line_item_html', 'woocommerce_order_item_line_item_html', 1, 3); /** * Callback Listener for customised line item functionality in the admin. */ function woocommerce_order_item_line_item_html($item_id, $item, $order){ // Add your custom line item functionality. // A good example would be order fulfillment for a line item. }