AR/CTL directory
At execution of the application program, AR/CTL merges the option values from the records that apply to the execution and creates the AR/CTL directory in main memory, as shown in the following figure. The merge process does not change the original option values stored in the records in the REGISET.
AR/CTL loads the directory in main memory with the values from the global options record. AR/CTL replaces the values in the directory with the values from the least specific record. Then it replaces the values with those from a more specific record, and so on, until it has replaced the values in the directory with the values from the most specific record. Any values you do not specify in a more specific record remain unchanged from the values set in a less specific record.
How AR/CTL merges processing option values
