The absence of any hazard class or division or a blank space in the table indicates that no restrictions apply.
*: This indicates that segregation among different Class 1 materials is governed by the compatibility table in 49CFR 177.848(f)
X: These materials may not be loaded, transported, or stored together in the same transport vehicle or storage facility during the course of transportation.
O: Indicates that these materials may not be loaded, transported or stored together in the same transport vehicle or storage facility during the course of transportation, unless separated in a manner that, in the event of leakage from packages under conditions normally incident to transportation, commingling of hazardous materials would not occur.
A: This note means that, notwithstanding the requirements of the letter 'X', ammonium nitrate fertilizer may be loaded or stored with Division 1.1 or Division 1.5 materials.