Not sure if this is true, but even if it was it hasn't stopped the SMH and Daily Telegraph.
It's up for interpretation:
http://www.austlii.edu.au/au/legis/nsw/consol_act/ea1990104/s18a.html (EDIT: yes, just saw Absolutezero's post)
But my first point still stands. There has never been an official list of school rankings; basing school rankings off Band 6's is meaningless. It doesn't differentiate between a school full of 90 scores and a school full of 99 scores. Nor does it take into account the relative difficulties of each course (which is what UAC does); a school with a larger percentage of 90 scores in say Dance, Aboriginal Studies, etc. (no offense), is apparently better than a school full of 89's in say MX2, Physics, Latin etc.
The first 10-20 schools might be accurate, but after that, it can be taken one way or another.