When the JOB is spawned, VMS creates the environment for the new process by copying the environment of the process issuing the JOB command and making a few minor modifications.

When the JOB is DETACHED, as it is by default, GT.M creates a new VMS job by running LOGINOUT.EXE. LOGINOUT.EXE performs the same tasks for the new job as it does for an interactive login session, except that it assigns the process-permanent logical names for I/O based on the processparameters. If the JOB command does not explicitly specify these processparameters, GT.M provides default values.