@b0rk Another obscure character is Ctrl-Y (DSUSP, delayed suspend). Similar function to Ctrl-Z, which sends SIGTSTP immediately. However, Ctrl-Y is buffered up by the terminal driver with other input. When it is about to be read by the program, the driver sends SIGTSTP at that point and discards the Ctrl-Y.

I think both DSUSP and DISCARD are BSDisms. Various man pages seem to indicate they aren’t supported on Linux.