If the sign was simply a no parking sign or a loading zone/standing zone sign, then you were wrongly ticketed. But, if the sign said "no stopping no standing" then you were in the wrong. Additionally, if the ticket was never handed to you or placed on your vehicle at the time of occurence, that is grounds for dismissal as the chicago municipal code explcitly states that parking tickets must be handed to the operator of the vehicle or placed on the vehicle itself. I have seen parking tickets dismissed because the ticket was only issued thru the mail because the ticketing official did not have time to finish writing the ticket before the vehicle left the scene. I myself have successfully had a ticket dismissed for that very reason. But, you must appeal within 21 days of receiving that letter. Don't wait-- appeal now. And appeal in person for the best chance of winning. You will be issued a one week period in which to appeal the ticket anytime during hearing center business hours, which makes appealing more convenient then if it was only during a set hearing time. If you wait, the fine will double and you will lose your chance to appeal. And your car will be booted and/or towed if this is at least your third unpaid parking ticket. Good luck.