I'm trying to think of a way to graphically represent the idea of credit, as in money owed. Are there any conventional solutions to this?
When I thought of someone owing me money, the first thing that came to mind was a hand extended forward, palm up. As in, "give me the money." From there, I thought of the bill collector at the door. Not sure if that idea can be converted into whatever you want to do or if that's the kind of connotation you want to carry, but I thought I'd throw it out there.
Also, if the target is more accounting-oriented, I remember that debit and credit were literally defined as 'the left and right side of the ledger' in my college accounting class. As someone who knew little about accounting, I thought this was a tremendously meaningless definition, but if you're in that world it makes sense and would be recognizable.