Commercial banks will have to do more than just look at the credit rating on a security before deciding it qualifies as a potential investment under a proposed rule issued by the Office of the Comptroller of the Currency this week. The Federal Deposit Insurance Corp. is scheduled to consider a similar proposal next week. Under marching orders from the Dodd-Frank Act, bank regulators have been removing references to external credit ratings from a variety of regulations – even though banks themselves don’t agree with the change. Most commenters on earlier proposals from...