Adding comments to an order is a good way to keep track of any extra details related to an order made in the store on your website.
To add a comment on an order first go to the list of orders on your site within your store.
Next, click View to the left of the order that you want to add a comment to.
Clicking on View will take you to the Order Details page.
The Comments tab is where you'll view and create new comments for the order. The tab also shows the number of comments for the order you're viewing.
You'll see a chronological listing of comments in the Comments tab, containing the name of the administrator user who made the comment, the date and time it was posted, and (of course) the comment itself.
To add a new comment, scroll down past the comments until you see the Order Comment text area.
Enter your comment here and click Add Comment when you're finished. It will cause the page to reload. Clicking the Comments tab again will show you the comment you just created.