A description of the conditions under which an AIS functions, based on the sensitivity of data processed and the clearance levels and authorizations of the users. Four modes of operation are authorized:

1) Dedicated Mode

An AIS is operating in the dedicated mode when each user with direct or indirect individual access to the AIS, its peripherals, remote terminals, or remote hosts, has all of the following:

- A valid personnel clearance for all information on the system.

- Formal access approval for, and has signed nondisclosure agreements for all the information stored and/or processed (including all compartments, subcompartments and/or special access programs).

- A valid need-to-know for all information contained within the system.

2) System-High Mode

An AS is operating in the system-high mode when each user with direct or indirect access to the AIS, its peripherals, remote terminals, or remote hosts has all of the following:

- A valid personnel clearance for all information on the AIS.

- Formal access approval for, and has signed nondisclosure agreements for all the information stored and/or processed (including all compartments, subcompartments, and/or special access programs).

- A valid need-to-know for some of the information contained within the AIS.

3) Compartmented Mode

An AIS is operating in the compartmented mode when each user with direct or indirect access to AIS, its peripherals, remote terminals, or remote hosts, has all of the following.

- A valid personnel clearance for the most restricted information processed in the AIS.

- Formal access approval for, and has signed nondisclosure agreements for that information to which he/she is to have access.

- A valid need-to-know for that information to which he/she is to have access.

4) Multilevel Mode

An AIS is operating in the multilevel mode when all the following statements are satisfied concerning the users with direct or indirect access to the AIS, its peripherals, remote terminals, or remote hosts:

- Some do not have a valid personnel clearance for all the information processed in the AIS.

- All have the proper clearance and have the appropriate formal access approval for that information to which he/she is to have access.

- All have a valid need-to-know for that information to which they are to have access.