The CRC (non-state) classes can also go into module.pmod, since they're small. A class doesn't _have_ to be in its own pmod file to behave like a module. In a module.pmod file one would do something like this to create a submodule:
protected class _MySubModule
{
...
}
_MySubModule MySubModule = _MySubModule();
Afaik there's no established name convention for this kind of classes.
I just picked a name with a "_" prefix in lack of any better ideas.
