This is about C, not C++. Though I haven’t been there in years, I chuckle to think what would have happened if you made this mistake on that news group.
Pretty sure OP is referring to this part of the comment they were replying to:
> Users posting to comp.lang.c through Google Groups were a problem -- especially with the recent bug that caused GG posts to comp.lang.c++ to have the "++" quietly dropped.
> Users posting to comp.lang.c through Google Groups were a problem -- especially with the recent bug that caused GG posts to comp.lang.c++ to have the "++" quietly dropped.