Where can I find information about exit-values below 300?

Hello, can anyone tell me, where I can find out the meaning of exit values of a program compiled with GPC? I know this sourcefile, where the values from 300 to 925 are listed. But what about the others? I did find out, that 8 means a division with zero, 11 occurs, when i tty to dereference nil, and 15 is returned, if i kill the process from outside. Is there a list of those values somewhere? Greetings, Michael