The name "duck sauce" comes from Chinese restaurants in the U.S. which mistakenly served the sauce with the pancakes that go with Peking Duck, as opposed to serving it with hoisin sauce, which is the authentic practice.
The name "duck sauce" comes from Chinese restaurants in the U.S. which serve it with roast duck. It is sometimes mistakenly served with the crepes that go with Peking Duck, as opposed to serving it with hoisin sauce, which is the authentic practice.