Information may be classified as national security information by a designated original classifier of the Department if it is determined that the information concerns one or more of the categories described in Sec. 1.5 of E.O. 12958. The levels established by E.O. 12958 (Top Secret, Secret, and Confidential) are the only terms that may be applied to national security information. Except as provided by statute, no other terms shall be used within the Department for the three classification levels.