Most parents are very good at recognizing when their children have a problem. Most children who have a problem know the behaviour and 'codes' which will signal to a parent that there is a problem.
This particular code is possibly redundant because parents are always saying: 'What is the matter with you?' The value of the code is that it is simple, direct, neutral and impersonal. It is a genuine inquiry as to what the matter might be.

Many youngsters find it difficult to launch into their concerns and problems unless they are specifically asked to. The code provides the request.

The code covers a broad spectrum from serious matters like a career choice to a minor upset such as when a youngster seems to have been favoured in some small matter.