Ohhh that. I think I know what you're referring to.On the paper, around the border there is little black half-squares that create a grid around the paper, and underneath it says something like "do not write in this section"
Its located about halfway up the header and footer; you can't miss it.
As long as you write in between the grid, everything should get marked, provided the teachers know what it relates to.
Example: you may run out of room for a question so you add more points at the bottom of the page and specify what question its part of - That should be fine
I had a chat to my brother (he did his hsc in 2010) and he said... they give us an extra writing booklet. Do you think it's better to continue our answer beyond the lines on the question booklet or write it in the external writing booklet? wouldn't the marker feel a bit hassled and lose track of what they were reading if done so?