It is one of the three Customer-Supplier patterns. This pattern is the opposite of the Anticorruption Layer Pattern and in this context, it is the upstream bounded context that is in control and the supplier has to provide the best service possible. This pattern helps to protect the customers from changes and decouples implementation from public interface.
Note
Because the consumer is in control of what it being provided with, it doesn’t mean it needs to conform to its ubiquitous language. It just exposes a protocol for a consumer in an integration-oriented language.