I've completely banned any code that can't be explained. I've had my CTO send me code at 3 AM to implement and when I ask him what I'm looking at he just says it doesn't need review, just push it.
Uhh, no sir, I'm not doing shit because you've handed me GCC and we're MSVC.
After I bitched endlessly to the CEO about that he said I have final say on what goes into the project.