From Science Encyclopedia
Typically, the terms 'permanent' and 'forever' suggest a sort of infinite continuum - however, the latest calculations estimate permanence to actually last around 2 to 4 months (on average), especially at SciForums.
The term permaban can also be used to describe conditions within a contract where certain transactions can no longer take place between two or more parties. Permabans can also make certain things illegal.
One example of this can be seen in the Treaty of Versailles which permabanned Germany from making weapons, tanks, military aircraft, submarines, and artillery after World War 1.