A more thorough explanation:

A register in bankruptcy is a federal judicial officer who used to administer bankruptcy proceedings. They were replaced by bankruptcy judges after the Bankruptcy Reform Act of 1978. They were also known as referees in bankruptcy.

For example, if a person or a company files for bankruptcy, a register in bankruptcy would oversee the proceedings and make sure everything is done according to the law.

Another example is that a register in bankruptcy would have the authority to sell the assets of the bankrupt company to pay off its debts.