I think I found the answer to my question in chapter 26 (not 27 as the practice question tells me to look): Is it because the road is divided into lanes by the broken white line that parking is not permitted on the street in general?

The English practice test question shows an image of a car parked BEFORE a blue parking information sign. I understand that parking is allowed AFTER the sign. But I don’t understand why this car is not allowed to park BEFORE the sign also. It is a regular road in a built up area with a broken white line splitting the road into 2 lanes. No signs prohibit parking anywhere on the street. So why is the car not allowed to park both after and before the sign? The question tells me to look in Lesson 27 for the answer, but it is not there.

Thank You