You manage to activate it and inform the public at the same time. Once SI see this do you not think they will ensure people cannot use it for FM14? Being able to use it for a short time is completely stupid compared to being able to use it for a long time by keeping it secret.
By all means...
I would ask people who do have access to the Advanced Rules to not disclose how to activate it in public - otherwise expect there to be no Advanced Rules moving forward.
Well done for posting this out in the open, where SI can find and disable this for future releases.
I understand you want others to know, but this could be completely detrimental to all of us. I hope you understand what you have done.