Two or more instances of JES2 can share initialization statements while retaining unique values in those statements. A single initialization statement can affect multiple instances of JES2, allowing you to view the environment as a single image with one point of control.

System symbols can represent unique values in shared initialization statements. Each MVS™ system can define its own values to system symbols. When shared statements are processed, each MAS member replaces the system symbols with its own values.

Before you use system symbols in JES2 initialization statements, you must understand the types of system symbols, the elements that comprise them, and the general rules for using them. See z/OS MVS Initialization and Tuning Reference for details about planning to use system symbols. Then read the rest of this section for specific information about using system symbols in JES2 initialization statements.