No Parking sign
You may not leave a vehicle standing here, though you may usually stop briefly to load or unload people.
How to recognise it
This sign is a tall rectangle in white, the standard background for a rule you must obey. These carry the force of law. Ignore one and you have broken a traffic rule, not just a guideline. Most are white rectangles with black text, and the handful that are not, the stop and yield signs, get their own unmistakable shapes.
What the test wants you to know
Parking questions are really distance questions: most states ban parking within 15 feet of a hydrant and 20 feet of a crosswalk whether or not a sign is present. Learn your own state's numbers, because they vary.
Practise it
Reading about a sign is not the same as recognising it in half a second with an examiner watching. Every state road signs test on this site shows the sign and asks you to name it, then shows four faces and asks you to pick the right one.
Stop
Yield
Do Not Enter
Wrong Way
Speed Limit
One Way