About order notes
To add a note for a specific Order:
1. Go to your Orders list and select the order you wish to add a note to
2. Click the Edit button on the page that appears
3. If you wish to add a private note that is not visible to the customer, add it to the Notes field
3b. Alternatively, if you wish the note to appear to the customer on the invoice ensure that you complete the Customer Message field.
4. Click the Save Order button to confirm the changes