Even if it is legal, mixing case and non-case labels in the body of a switch statement is very confusing and can even be the result of a typing error.

Noncompliant Code Example

switch (day) {
  case MONDAY:
  case TUESDAY:
  WEDNESDAY:   // Noncompliant; syntactically correct, but behavior is not what's expected
    doSomething();
    break;
  ...
}

switch (day) {
  case MONDAY:
    break;
  case TUESDAY:
    foo:for(int i = 0 ; i < X ; i++) {  // Noncompliant; the code is correct and behaves as expected but is barely readable
         /* ... */
        break foo;  // this break statement doesn't relate to the nesting case TUESDAY
         /* ... */
    }
    break;
    /* ... */
}

Compliant Solution

switch (day) {
  case MONDAY:
  case TUESDAY:
  case WEDNESDAY:
    doSomething();
    break;
  ...
}

switch (day) {
  case MONDAY:
    break;
  case TUESDAY:
    compute(args); // put the content of the labelled "for" statement in a dedicated method
    break;

    /* ... */
}

See