On May 20, Moody's released its methodology for rating corporate synthetic collateralized debt obligations (CSOs). Report. On May 19, Moody's released its methodology for rating commercial mortgage backed securities (CMBS) in Europe, Middle East and Africa (EMEA). Report. On May 19, Fitch released its updated criteria for rating global aircraft operating lease ABS. Report. On May 18, Fitch updated its International Local and Regional Government Ratings Criteria. Report. On May 18, Fitch updated its U.S. Public Power Rating Criteria. Report. The content of this article is intended to provide a general guide to the subject matter.