What is the One exception to the Full Faith and Credit Clause is that one state?

The one exception to the Full Faith and Credit Clause is that a state may refuse to recognize another state's laws or judicial decisions if they violate its own public policy. For example, if a state has laws against certain types of marriages or contracts, it may choose not to enforce those from another state that conflict with its own values. This exception allows states to maintain their legal and moral standards while still generally respecting the laws of other states.