IEHIEB... names 2408

remainder snipped

Correct; IEHfoo would typically be a utility to maintain the OS (IEHPROGM, IEHMOVE, etc), while IEBbar would do something likely to be part of a production job. There were also some system utilities clbuttified as "Service Aids", originally distributed informally through CE channels but later incorporated into OS-360 (at release 18?) with IMx prefixes. (There was also the late, and quite unlamented, IHGUAP -- was there *anyone* who ever used it?)

Another distinction (not true in all cases) was that the IEH utilities played games with the JFCB (Job File Control Block, which contained information from a DD card). Where one normally had to have a DD card in a job step's JCL for every data set manipulated in the step, the IEH utilities usually required only a DD card pointing to each volume (normally, disk drive) that would be involved in the job step: when the utility needed to access a data set it would locate an appropriate JFCB, read it into memory, modify the data to make it refer to the desired data set, and then use OPENJ to open the data set as if the DD card had pointed to the data set.

Joe Morris