These fields serve as custom order specifications which are
asked from customer at the time of order placement. You must first create a custom
fields list and then add fields to it. You can also add a help image, which
will be displayed to the customers for help, with custom fields form.
Please note that you must link a custom list to products for
which you want a customer to provide specifications.
To add custom field list:
To add a custom field to the list: