Need to go back and add your location to your profile.
Differant locations can have differant codes there using.
What rail are you talking about? The hand rail.
Is this inside or outside?
Here's some general rules, may want to check with your local building dept. to verify.
If you are talking about the hand rail keep in mind the hand rail must return back to the wall (so an artical of clothing does not get caught on it)
And must be gripable. How many times have we all seen a hand rail on a deck that is just a 2 X 4 laying flat, that's not legal, it's to wide. Fine to do that but in addition you need one that's grippable.