How to add client details on a Picking/Packing Slip?

By default client info are not included in the Picking/Packing Slip. If you want to activate this:

1. Click on the Gear icon.
2. Open Document Types from the right menu.
3. Select Sales Order from the list.
4. Check the box next to "Client info on Picking/Packing Slip".
5. Click on Update to save the changes.