WORK File is a Work File
WORK This User Option indicates whether the file has been given the status of a Work file within the SM pubset, and hence whether it can be erased after a particular time period. This User Option is available from OSD V3.0.
The ONXSET WORK Variable Action (see page 5-) or the WORK-FILE parameter to the /MODIFY-FILE-ATTR command can be used to assign Workfile status to a file.
Selection parameter: Y | N