所有这些使得它成为一种实际可用的的支付系统的条件是：服务提供商必须要将唯一识别符与银行帐号或者信用卡链接起来。

All that's required to turn this system into a reliable payment mechanism is a service provider willing to link that unique identifier to a bank account or credit card.

youdao

相反，它只需要程序员将属性标记为持久性的，并识别出能代表对象唯一标识符(或者主键)的属性。

Instead, it requires the developer only to denote the attributes to be persisted and to identify the attribute to represent the object's unique identifier (or primary key).

youdao

例如，眼下并没有要求渔船必须有国际海事组织提供的识别码，它是全球公认且唯一的航运标识符。

Right now, for example, fishing boats aren't required to have an identification code from the International Maritime Organization, the only globally recognized identifier for shipping.

youdao