[quote=eyesonlyhacker]
I am pretty sure ODST is a UNSC Marine Corps unit only, and from a brief glance at the other CS it looks like everyone is ODST specific, and not on lone from other branches. So I think it is safe to say that everyone here is a marine.
[/quote]

From Halo Nation: The Orbital Drop Shock Troopers (ODST) are a special operations capable organization of the UNSC Marine Corps that specialize in orbital-dropped shock infantry and special warfare tactics.