Clear, communicative naming is important in code. It helps maintainers and API users understand the intentions for and uses of a unit of code. Using "exception" in the name of a class that does not extend Exception or one of its subclasses is a clear violation of the expectation that a class' name will indicate what it is and/or does.

Noncompliant Code Example

public class FruitException {  // Noncompliant; this has nothing to do with Exception
  private Fruit expected;
  private String unusualCharacteristics;
  private boolean appropriateForCommercialExploitation;
  // ...
}

public class CarException {  // Noncompliant; the extends clause was forgotten?
  public CarException(String message, Throwable cause) {
  // ...

Compliant Solution

public class FruitSport {
  private Fruit expected;
  private String unusualCharacteristics;
  private boolean appropriateForCommercialExploitation;
  // ...
}

public class CarException extends Exception {
  public CarException(String message, Throwable cause) {
  // ...