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.