//ACCT1  JOB  A23,SMITH,REGION=100K,ADDRSPC=REAL

This JOB statement indicates that the job requires 100K of central storage.

//ACCT4  JOB  175,FRED,REGION=250K

This JOB statement indicates that the job requires 250K of virtual storage. When the ADDRSPC parameter is omitted, the system defaults to ADDRSPC=VIRT.