Is Coastal Breathing the same as Diaphragmatic Breathing?

Is Coastal Breathing the same as Diaphragmatic Breathing? Hi all, I recently started reading "Beyond Stuttering" by McGuire and he talks about how coastal breathing can help reduce stuttering. Before I had read this book, I thought coastal breathing was the same thing as diaphragmatic breathing. But after doing a bit of research, I'm starting to think that coastal breathing is more so about breathing into the ribs such that they expand outwards while diaphragmatic breathing is breathing into the belly? Could anyone please clarify?