Even if it is legal, mixing case and non-case labels in the body of a switch statement is very confusing, and could mislead developers discovering this piece of code.
switch (variable) {
case 0:
/* ... */
myLabel: // Noncompliant
result = 0;
break;
case 1:
/* ... */
default:
/* ... */
}
switch (variable) {
case 0:
/* ... */
result = 0;
break;
case 1:
/* ... */
default:
/* ... */
}