DevOps, CI/CD and Automation

Basically I'm running a process in C# that execute multiple reports through Process.Start() method, once completed I'm checking the Process.ExitCode to verify if it was a successful execution.

In the arguments for the command line execution I'm passing the ERRFILE=ErrorFile.txt argument to have an error log,.

Usually after a successful execution, by 'standard' (actually best practice I think), the exit code of an application is 0, but in some reports I'm having exit codes like 4, and no errors are logged in the ERRFILE.

I've checked the Reference Manual already, but I can't find any reference to command line error/exit level/code.
If somebody has the RWRUN60.exe process exit codes I'd appreciate it.

Thanks in advance.