DFSORT allows separate sets of installation defaults for four invocation installation environments, as follows:

JCL-invoked (ICEAM1)

DFSORT invoked directly (that is, not through programs) by batch jobs

Program-invoked (ICEAM2)

DFSORT invoked through batch programs

TSO-invoked (ICEAM3)

DFSORT invoked directly by foreground TSO users

TSO program-invoked (ICEAM4)

DFSORT invoked through programs by foreground TSO users