[G3] All proper nouns...

[Bigsmith] I have to acknowlege that I have misled everyone by stating, wrongly, that the answer is not a proper noun. It is. How I came to say that it isn't is beyond me. Truly sorry. *Hides face in embarassment*

[GIII] None of the above three.

[Everyone] I will answer all of the unanswered questions above AND provide a proper clue a little later on today.

[Kim] No worries - everyone else seems to have ignored that answer!

[Bigsmith] It seemed absurd...

[Quendalon] "It" is currently populated by living people.
[Rosie] "It" is not exclusively in the South Pacific and therefore not exclusively South of 45^oS. I fully understand and sympathise with your frustration and I think it will be necessary to draw this particular round to an end within the next 48 hours.
[Dujon] "It" is not a dissolved union or federation
[CdM] "It" could be said to be an area of disputed territory that lies partly within Antarctica.
[Chalky] You deserve a better clue than my miserable efforts so far and I shall try to provide a decent clue in a separate post passim.
[INJ] Some of "it" has military significance.
[Bigsmith] A fair summary, which I would like to supplement, if you don't mind.

1. We have recently established that, although it is abstract, it is a proper noun, despite my asserting the contrary, which will probably haunt me forever.
2. The question of whether it exists or not depends entirely on your point of view, which is to say that some people would assert that it exists and others would assert that it does not. Its very existence is a matter of dispute. It is my belief that it does not exist and is therefore abstract.
3. To the extent that it does exist, it purports to be a country, that is to say, those who believe that it does exist refer to it by a name (yes, a proper noun; sorry, again).
4. To the extent that it does exist, it is substantially, but not exclusively in Australisia/Oceania. The question of the whole, or part of Antarctica has some up more than once and is relevant.
5. To the extent that it does exist, its territorial rights are in dispute.
6. To the extent that it does exist, it does not comprise a single landmass, but several.

There is a strong biblical connection.

I don't recall Antarctica being mentioned in the Bible.

{Bigsmith] Not me! It's been driving me crazy. In fact i almost asked a couple of days ago if Kim was sure. But I'll still forgive him. Maybe.

In other words, is it the designation of this place that is under existential dispute, or the very place itself?

... and I am aware that CdM mentioned Atlantis some time ago :-)

[Rosie] No.
[Raak] No.
[Chalky] Its Wiki entry does not provide the landmass area in m², but I would say that it is not "really, really big" (in comparison to, say, Africa).
[CdM] We can all agree that the landmasses that comprise it all really do exist. They are, without doubt, the Animal, Vegetable and Mineral parts of this. What we are testing, I think, is the Abstract element.
[Chalky] No.

[CdM] Yes, I too found the proper noun thing frustrating, glad it is clear now. I think I can bring myself to forgive Kim...just about!