It's a place holder. The previous standard was C++98. The last C standard was C99. C++0x means "The C++ standard that will be finalized between 2000 and 2009."

"C++" isn't a particularly great name itself, apparently they wanted to continue the tradition

Can someone actually explain what it means? I'm not a professional programmer, but I haven't seen notation like that.

Unfortunately, C++0xDeadBeef didn't work for vegetarian members of the committee.

Simple solution: Use C++3735928559 instead.