Raklet has standard fields for the data that you want to keep about your contacts, but you can easily create custom fields for the info special to your organization.
You can create your custom fields while your data import process by denominating the related column.
You can decide on your custom fields through the admin panel as well. To see all your fields in the system and create the new ones, go to your email at the lower left corner and then click Settings. You will see fields section. Click create a custom field and write down the name. This fields will be added automatically to the profiles of your contacts.