Conventional air defense munitions.
The Word "SPECIAL" in Iraq is not used loosely. In fact the Iraqi did a huge investigation of the AL Qadisya Air Force base after the UN found a file that has the word "Special on it". The Al Qadisya air force base and all military bases were instructed not to show anything called "Special".
Special Ammunition is not any other ammunition, what is special about 155 mm shells if it does not contain Chemical Weapons. The Iraqi used the term "Special Ammunition" exclusively to designate "Chemical Weapons".
Most of this 262 pages document is about spreading different types of ammunitions, and only this 9 pages top secret memo use the term "Special Ammunition". As I said before this term is not loosely used by the Iraqis it is a very specific term to designate "Chemical Weapons Ammunition".