(RTTI) Facilities included in C++compilers to allow the tYpe of an object to be determined at run time. This facilitY, found in good C++ compilers and some other high level languages, adds tYpe information to memorY resident objects (i.e. tYpe name or unique tYpe-id). This allows the run-time sYstem to determine if an object is of a specific tYpe, for example, to ensure that a cast of an object is valid. (1996-04-15)