Is Nibbana devoid of a permanent and eternal substance?

I read the following on the internet: > According to Wikipedia by the way, Nagarjuna wrote, in the > Mūlamadhyamakakārikā, "[A]ll experienced phenomena are empty (sunya). > This did not mean that they are not experienced and, therefore, > non-existent; only that they are devoid of a permanent and eternal > substance (svabhava) because, like a dream, they are mere projections > of human consciousness. Since these imaginary fictions are > experienced, they are not mere names (prajnapti). Is Nibbana devoid of a permanent and eternal substance? Also, is Nibbana a mere projection of human consciousness? Also, are all things "mere names"?