Correct! It's a language defined ad-hoc by GCC and Clang. GCC's man page describes its behavior with '-fno-exceptions' to be essentially: act like a normal C++

Correct! It's a language defined ad-hoc by GCC and Clang. GCC's man page describes its behavior with '-fno-exceptions' to be essentially: act like a normal C++ compiler, except produce code which calls abort() where it would otherwise have engaged the exception throwing machinery. That defines a kind of "C++ with exceptions disabled" language, but it's not a standard.