To prevent the number of parmlib definitions from increasing with each system that is added to a sysplex environment, you can share parmlib members across systems. If systems require unique values in those parmlib members, you can code them so the different systems can supply unique values in shared parmlib definitions.

System symbols are the elements that allow systems to specify unique values in shared parmlib members. When specified in a parmlib definition that two or more system images are to share, system symbols resolve to unique values on each system.