|ISB "Agent" rank|
We also have to, within this proposed rank structure, take into account ISB Colonel Wulff Yularen (plaque = 3 red squares at left, 3 blue squares at right) and another (unnamed, I think) white uniformed ISB agent also seen on the Death Star (plaque = reverse of Yularen).
Finally, as an upper bound, we need to account for the plaque worn by Armand Isard (and later by his daughter, Ysanne). It is the equivalent of the Imperial Navy's Fleet Admiral. Seems about right. The Tarkin book held some hints as to the ranks of various top level "cabinet" positions within the Military Intelligence, etc, so I will have to do some cross-checking.
Curious about the other rank structures and insignia I've cobbled together? Here are links to the Imperials and the Rebels.