This document proposes an IDL to C++03 mapping to complement the existing IDL to C++11 mapping. It suggests extending the C++11 mapping specification to optionally support C++03 features, to address projects still using C++03. Specifically, it would replace some C++11 constructs with C++03 equivalents and make certain text optional based on the C++ flavor. This approach could be done as part of an RFC to extend the C++11 mapping specification. The document discusses compiler support for C++11 and the gradual migration to it, noting that a C++03 mapping would fill the gap for projects not yet upgraded.