An interim clearance allows a person to have access to collateral classified information (at the level requested without a caveat) while his or her final clearance is being processed. For example, a person with an Interim Secret may have access to a document marked Secret, but not a caveated one, Secret COMSEC..
Enlisted Air Force ranks are broken down into three levels: Airmen (E-1 through E-4), Non-Commissioned Officers (E-5 and E-6), and Senior Non-Commissioned Officers (E-7 through E-9). The Air Force is the only one of the five branches of the U.S. military where NCO status is achieved at the grade of E-5.
The year 1991 also saw the last major change to the enlisted rank insignia. In October 1991 General McPeak and Chief Master Sergeant of the Air Force Pfingston announced that the senior NCO tier would have new chevron layouts and that all chevrons would have a white star in the center.