The Commission's Uniform Systems of Accounts provide that in order to maintain uniformity of accounting, regulated entities must submit questions of doubtful interpretations to the Commission for consideration and decision. The Commission and its Chief Accountant provide guidance to, and respond to inquiries from, regulated entities on the implementation of standards issued by the Financial Accounting Standards Board and existing or emerging industry-wide or entity specific accounting issues within the context of the Uniform Systems of Accounts. Past guidance letters have addressed such issues as accounting for uncertainty in income taxes, accounting for the funded status of defined benefit postretirement plans, and the appropriate accounting treatment for earnings on use-restricted debt funds used for construction. The advice provided in guidance letters issued by the Chief Accountant represent the views of the Commission's accounting staff and serve as controlling accounting guidance for regulated entities unless or until superseded by rehearing or other Commission action. However, neither guidance letters issued by the Chief Accountant nor informal advice provided through discussions with the Chief Accountant are binding on the Commission and are not controlling precedent for ratemaking purposes.