http://www.builderbill-diy-help.com/formwork-stairs.html
I think that Aussie N12 is 3/8 rebar and N16 is half inch (number of 32nds).
Also... The plan is for a free standing flight of steps. No rebar shown in steps on ground.
Note rule that says you have to have a landing if you have more than N steps. Code is same here.