[Straight Vermonter]

They show a rectangle in the diamond instead of w/out the X inside. I am assuming that this shows "the division" is now in reality a brigade.

[Cboldt]

The big "X" on the inside means there is infantry present. A "Rectangle" or "rounded rectangle" inside indicates the presence of armor. Some units have both, infantry and armor, which is termed "Mechanized Infantry".

There is also a symbol above the diamond (or outer rectangle, for coalition forces). If there is one small "x", it is a Brigade, "xx" is a Division, and "xxx" is a Corps.

I see some unit force identified with "iii", the "Airborne Infantry Regiment" to be exact. I would guess that the distinction between "X" and "i" designations is that "i" refers to infantry force size, and "x" reers to armor force size (with some implied haman strength to support a unit of armor).

Anyway, the above is my best guess, just from examination of the maps. I don't see any change in force ascribed to Ham1, Neb6 or Med2. FWIW, Medina is the Iraq 2nd Division. There is ONLY a Med2, etc.