title: Woocommerce - add serial to products in orders
body: <p>I am looking for a way to add a serial number to each sold product, in the order display in WooCommerce. What I need is a manual solution, where the S/N of the sent product is added to the order before the package is sent. I have tried to show it on the following picture:</p>
  
  <p><img src="https://i.stack.imgur.com/sggWt.jpg" alt="Possibility of adding a serial"></p>
  
  <p>Originally, I thought about implementing it as a product meta (without really knowing how) but I realized that product metas can only be altered when the order is set on hold and not while processing.</p>
  
  <p>Any ideas aboout how to proceed? Thanks already!</p>