Credit is good. If by some lucky chance you happen to come by some actual money and it accidentally finds its way into your bank account, it's a credit. The real money you have in your account is a credit balance. Having a credit balance means you're 'in the black' and HAVE money.

Does AC/DC's 'Back in Black' got anything to do with black money ?

Thanks Chris. But it will still take me more examinations to finally become what you complimented me...