Which are common DDD (Domain-Driven Design) patterns?

Specification pattern is a common pattern used in DDD that encapsulate business logic to respond to one question.

public interface ISpecification<T>
{
    bool IsSatisfiedBy(T aSource);
}

public class CustomerHaveDiscountSpec : ISpecification<Customer>
{
   bool IsSatisfiedBy(Customer aCustomer)
   {
       /* ... */
   }
}

Which other patterns are common in Domain-Driven Design?