It's no secret that parking in the city is a bitch. So we've enlisted local parking guru and author of Finding the Sweet Spot, David La Bua, to dish out weekly tips on navigating the ins and outs of city parking.

There are more than 23,000 parking meters, 200,000 traffic signs, 1,100 traffic signals, and 880 miles of lane lines on the streets of San Francisco. It’s no wonder that navigating and parking in our city can be frustrating, and receiving parking tickets has become just a part of daily SF life.

But, there is a little known rule if followed, will save you time, money, and frustration for the rest of your parking years. It’s a rule that is not posted anywhere, and has probably already cost you several hundred dollars. Your driving instructor didn’t tell you about it. Your Grandpa doesn’t even know about it. Do you?

Which of these is an official rule in the SF parking code that is enforced daily:

A) All vehicles parked in SF must have a political rant of some sort on the bumper

B) Cars may not be parked in any one space for more than seven days

C) Each parking sign is enforced for 100 feet in each direction

D) Each parking sign is enforceable on both sides of the street

E) All of the above

F) None of the above

Check back at 4:30 for the answer. It could save you hundreds of dollars in parking tickets!

Image via sean dreilinger on Flickr.com