After you have specified the data set characteristics in the DCB and DCBE macro, you can change them only by changing the DCB or DCBE during execution. See Changing and Testing the DCB and DCBE. The fields of the DCB discussed in the following sections are common to most data organizations and access methods. The DCBE is for BSAM, BPAM, QSAM, and BDAM. For more information about the DCB and DCBE fields see z/OS DFSMS Macro Instructions for Data Sets.