Try being friendly in your PMs letting them know about the guidelines. Otherwise, just fix it and move on. Only request a ban if it gets serious.
My goal is to reduce the need to fix press thread to zero so that I literally eliminate the need for moderation. If people aren't reading my PM or showing that they understand the guideline, then it is one more person to moderate in the future.
With a temporary ban, I can force them to learn rather than avoiding reading the thread they post in or avoiding reading PM.