In general, application programmers can override the defaults in the DBCAREA in order to reflect conditions appropriate for the application.
The application does not directly access the HSHSPB.
The settings in the DBCAREA after calling DBCHINI are copies of the values contained in the HSHSPB and can be modified by the program.
CLIv2 must be able to get defaults from the accessible HSHSPB. The program will fail if the HSHSPB is not available.