The above JCL references PT@JBVAR, the job variable file that contains the variables used in the script examples.
Variables are used for the information that would most likely change for different users. Thus the changes are localized to the job variable file, and the script examples themselves are static.
There are several changes necessary for proper execution of the JCL.
Note: The FileName attribute format used to specify the z/OS dataset for each script can be changed.