A lawyer who receives client or third-person money keeps one pooled, interest-earning trust account for sums that are small or likely to be held only briefly. This is Iowa's IOLTA account. The lawyer tells the client or outside party that net interest on the pooled account (after allowable monthly service charges) goes to the supreme court's Lawyer Trust Account Commission rather than to them.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.