Data Set Organization (DSORG)

DSORG specifies the organization of the data set as physical sequential (PS), partitioned (PO), or direct (DA). If the data set is processed using absolute rather than relative addresses, you must mark it as unmovable by adding a U to the DSORG parameter (for example, by coding DSORG=PSU). You must specify the data set organization in the DCB macro. In addition:

Unmovable and IS data sets cannot be system managed.