This is a guide and an explanation as to how you (the OP of a thread) can get it Re-opened once it is closed.
If you have something to add which is of value to the discussion but the thread is closed then PM the @ForumStaff, we will Re-open the thread for you.
You can only request your thread to be re-opened if you are the OP (creator of the thread). Same as if you want your thread closed.