The source node in most cases contains the sample message as written by the developer. If it looks like a dot-delimitted string such as "form.label.firstname", then the developer has not provided a default message.

e-commerce e-commerce key: breadcrumb.ecommerce Save Save key: shipping.save Country Country key: shipping.table.country Currency Currency key: shipping.table.currency Shipping cost Shipping cost key: shipping.table.shipping_cost Shipping method Shipping method key: shipping.table.shipping_method State State key: shipping.table.state Value of goods Value of goods key: shipping.table.value ZIP ZIP key: shipping.table.zip Manage shipping costs Manage shipping costs key: shipping_management.table.title Shipping management Shipping management key: shipping_management.title