Bear Proof containers along the AT?

Does anyone know if bear proof containers are required along any section of the AT?

I only know in the Smokies you must hang on provided rigs, also must camp at designated shelter/sites which contain said hanging poles.

Bear proof containers are not required on the AT. It is highly recommended that you hang your food bag. In some areas that seems to be more prudent because of the mice rather than the bears.

Furlough

Not sure if this is the correct thread or forum because I just registered. I want to purchase a used URSACK. Thank you. Joe