So, how much is your pay? 
Coming back to the point, i think the HR specifically tell you or
is in your terms and conditions that YOU are NOT supposed to
divulge your pay to other people in the firm.
This is to prevent dissention in the ranks and people getting
unhappy, like why same grade, same qualifications, but different
pay, etc.
But as companies more and more follow the standard pay structure,
this becomes more or less clearer as how much your pay is when you
reach this position or grade etc. 