Different dictionary in New South Wales, Australia?

My writing textbook on page 446 says this:

Use local conventions regarding punctuation, spelling, and mechanics. Be aware that these conventions differ from place to place, even in the English speaking world. For instance, the Australian state of New South Wales uses a different dictionary for spelling than all the other Australian states.

I can't seem to find anything backing up the statement about the dictionary. The author does not appear to cite his source for this information.

In short, does New South Wales really use their own dictionary?

The textbook is Markel, Mike. Technical Communication. 10th ed. Boston: Bedford/St. Martins, 2012. Print.

Whenever the term "official dictionary" is thrown around in Australia, it is usually in reference to the Macquarie dictionary which is considered the country's "national dictionary". The Macquarie was born in 1981 and continues to be based in Sydney, New South Wales. I suspect that the excerpt from the tenth edition of the book cited by the OP has not been updated since its first few editions; it is possible that the Macquarie was initially only prescribed in the state of NSW in the 1980s.

Both Oxford and Harper-Collins publish dictionaries for Australian English. While some terms can vary from state to state, spellings, as far as I know, do not. It is possible that in the early 1980s, the effects of spelling reform were still prevalent which could have led to inconsistencies. But I do not believe that any dictionaries bought into it.

The official Australian language is Strine - fair dinkum.
Dictionaries can be hard to come by.

References below, cobber:

Oxford dictionary Strine
Extract slightly abridged ...

• Strine Pronunciation: /strʌɪn/
  Definition of Strine
  noun
  [mass noun]
  the English language as spoken by Australians; the Australian accent, especially when considered pronounced or uneducated:
  I found myself speaking Strine within minutes of arrival
  arriving in Sydney, he applied for a job thinking that copywriter was Strine for copy typist
  [count noun] an Australian:
  iced beer stops up the nose—that’s why you Strines talk so funny

Global Citizens - A guide to Strine

Small sample:

• Ace! - Excellent! Very good!
  Ankle biter - small child
  Aussie battler - the ordinary working person.
  Back of Bourke - a very long way away
  Back of beyond - any remote, inaccessible and sparsely populated area
  Barbie - barbecue
  Barney - noisy fight or argument.
  Bewdy - great, fantastic
  Bikkie - biscuit
  Billabong - an ox-bow river or watering hole
  Billy - large tin can used to boil water over a campfire for tea
  Bludger - lazy person, somebody who always relies on other people to do things or lend him/her things
  Blue - fight
  Clobber - clothing or equipment.
  Dag - a funny person, nerd, goof
  Daks - trousers
  Damper - bread made from flour and water
  Fair dinkum - true, genuine
  Flake - shark's flesh
  Furphy - a lie, a fib

Urban Dictionary Strine