Read only Unique ID for this card. Generated by Square.
The ID of a customer created using the Customers API associated with the card.
An optional user-defined reference ID that associates this card with another entity in an external system. For example, a customer ID from an external customer management system.
Current version number of the card. Increments with each card update. Requests to update an existing Card object will be rejected unless the version in the request matches the current version for the Card.