31. What is COND=EVEN ?
It means execute this step even if any of the previous steps, terminated abnormally.

32. What is COND=ONLY ?
It means execute this step only if any of the previous steps, terminated abnormally.

33. The disp in the JCL is MOD and the program opens the file in OUTPUT mode. What happens ? The DISP in the JCL is SHR and the program opens the file in EXTEND mode. What happens ?
Records will be written to end of file (append) when a WRITE is done in both cases.

34. What are the differences between JES2 & JES3 ?
JES3 allocates datasets for all the steps before the job is scheduled. In JES2, allocation of datasets required by a step are done only just before the step executes.

35. What is the difference between specifying DISP=OLD and DISP=SHR for a dataset?
DISP=OLD denotes exclusive control of the dataset; DISP=SHR means there is no exclusivity.

36. What is the purpose of the PARM keyword in the EXEC statement?
The value after the PARM= specifies control information to be passed to the executing program of the job step.

37. What is the difference between BLKSIZE and LRECL?
LRECL is the logical record length , where as BLKSIZE is multiples of LRECL

38. How is the keyword DUMMY used in JCL?
For an output file DUMMY specifies that the output is to be discarded. For input it specifies that the file is empty.

39. What are three parameters you can specify on Job statement as well as on exec stmt ?
Time, Region and Cond parameters

40. How do you restart a step in JCL?
Use RESTART=step name.