Admiral Ozzel has them on both sides of his uniform (upper chest). Most Imperial officers seem to have them.
Han, pictured also here, has three such cartridges on his jacket. I'd like to make such a jacket and use anything that looks like them. I figure they are most closely related to cartridges for guns. (which is what I imagine they are in the films).
But does anyone know the real scoop on them? What is their purpose in the Star Wars universe?
And Han Solo: