Green’s Dictionary of Slang

1. (Aus.) the boundary between civilization and everything else, i.e. the wilds, the back of beyond; usu. in phrs. like beyond the rabbit-proof fence.

[1887		Exp. & Teleg. (Adelaide, SA) 3 May 3/4: A young rabbit has been caught four miles from Bourke on the protected side of the ‘rabbit-proof fence’].
1905		Sun. Times (Perth) 3 Sept. 8/2: [title] The Rabbit-Proof Fence.
1924		Sun. Times (Perth) 24 June 17/4: The twain are dressed in full war paint and are apparently ‘some style’ way back in some village on the rabbit-proof fence.
1941		Burra Record (Aus.) 17 June 4/5: A lot of ignoramuses who have had no education, know no culture, and have not been or seen beyond a rabbit-proof fence.
1954		Townsville Daily Bull. 5 Nov. 7/3: That God-abandoned border track [...] Once we’re through the rabbit-proof.
1963		‘Nino Culotta’ Gone Fishin’ 24: You wouldn’t find a politer bloke this side the rabbit-proof fence.
1986		C. Bowles G’DAY 81: The Outback is somewhere out the back of Bourke, Woop Woop and Bullamakanka, the other side of the rabbit-proof fence.
2003		Hansard (Aus.) 6 Aug. 🌐 There were lightning strikes beyond the rabbit-proof fence and local fire officers were reluctant to go in there and do something about it.

2. in fig. use, referring to something absurd or incomprehensible.

2005

posting at www.macupdate.com 20 Apr. 🌐 This is a bit beyond the rabbit proof fence. I can’t quite understand the criticism for not supporting an unreleased product.