FBI Index
(重定向自ADEX)

![FBI rep describing ADEX, 1975[12]](/uploads/202412/18/Adex15212.png)
The FBI Indexes were a series of personnel databases used by the FBI before the adoption by the Bureau of computerized databases. They were based on paper index cards. They were used to track US citizens and others believed by the Bureau to be dangerous to national security. The indexes generally had different 'classes' of danger the 'subject' was thought to represent.