Codes tend to be for the purposes of secrecy. Why? Because they hide the true meaning of information, whether it's a message or a map reference, or anything else that's meaning is to be kept from others.
The figures in the boxes on the left hand side of the page have been given letter codes that describe certain aspects of their appearance. Using this information you can find the code for the shape in the box on the right. There is a detailed explanation of how they work in the example question and answer, so just concentrate and think logically, and you shouldn't have any trouble.
Remember the advice of Alan Turing, the famous World War II code-breaker. He said, "We can only see a short distance ahead, but we can see plenty there that needs to be done." So, don't worry too much about what you can't see, just focus on the question in front of you, and enjoy our 11-Plus Non-Verbal Reasoning "Code Breaker" quiz number 2.