Appearance of Counsel (AO 458) is a form used by the U.S. Bankruptcy Court to indicate that a person or organization is appearing in a particular case. It is typically filed by attorneys or representatives of a debtor, creditor, or other party. The form allows the court to keep track of all parties involved in a case. There are two types of Appearance of Counsel (AO 458): Voluntary Appearance and Involuntary Appearance. A Voluntary Appearance is filed when an attorney or representative voluntarily appears before the court in a particular case. An Involuntary Appearance is filed when an attorney or representative is directed by the court to appear in a particular case.