Those are just informal names. C++98 is officially named ISO/IEC 14882:1998 so a version of the C++ standard released in 2098 would with the same naming scheme become ISO/IEC 14882:2098. I have no idea what we would call them informally that far in the future (maybe C++ is no longer maintained, we don't know) but an easy method would be to just refer to them as C++1998 and C++2098.