Simply put: $x::s and $x's are equivalent to perl. The reason for that is backward compatibility: the apostrophe was perl4's package name separator, on perl5, it's the double semicolon. But the apostrophe still works.

Sample code:

  $Foo'x = 123;
  print $Foo::x;
[download]

Result:

  123

The odd thing might be that this still doesn't produce a warning under perl5.8.3.