Enter the Password History setting in conjunction with the Allow Password Reuse setting (see Allow Password Reuse). If password reuse is not allowed, the system tracks passwords in a FIFO (First In, First Out) queue, up to the number specified by this setting.
Figure 16-33 Password History
You can reuse an old password after the specified a number (plus one) of other passwords have been used. For example: If you do not enable Allow Password Reuse and Password History is set to two, a user’s sequence of passwords might look like this:
You can reuse House*Magnet, since 2+1 other passwords have been used since House*Magnet.
A setting of 0 effectively enables immediate password reuse even if you do not set Allow Password Reuse.