// This rule specifies whether empty catch block are allowed.
// Catch blocks do follow a try statement in which something
// could go wrong. Hence, it was either forgotten or it is a
// sign of bad coding to have empty catch blocks.

...
try
{
    foo();
}
catch(FooException e)
{
    // something went wrong but no action is being taken
    // this migth cause big problems later for no obvious
    // reason
}

...
try
{
    foo();
}
catch(FooException e)
{
    // The stacktrace is printed to the error channel
    // Some other appropriate action might be taken as
    // well

    e.printStackTrace(System.err);
}