What exactly is an immune privileged area? And examples?

What exactly is an immune privileged area? And examples?
#AIIMSNov’18
I think tissues where Ig antibodies are not formed/available. Eg. cornea, seminiferous tubules. Read it in DAMS notes

Immune privileged sites are those where there is no immune response

The cornea, anterior chamber of the eye
Testis
Brain
Uterus