What can I do about the violation ticket that I received?

I was given a ticket earlier this year for doing a rolling stop at a stop sign. It was in a little neighborhood in a small town, or section of my city. I'm 17. I have recently learned or heard of a rumor that if the stop sign does not have a special sticker on the back saying that it was put in by the city or the government, or the state, a police officer cannot give me a ticket for it. It was a lot of hard work to get the money for the ticket and I'm going to court to fight. I have driven by many signs and ones on main streets have this sticker with a number on it and a different color but the same sticker. For example a yellow one had the number 12 and another one had the number 8 and was orange. If you need more info on this I would be more than happy to give it to you but I have not been able to drive by the sign I rolled yet to check because it is so far away.