You can only create PDS members as sequential record files using DFM. DDM client commands create stream files and can be used to create new PDSE members, but cannot be used to create new PDS members.

A DIR command shows PDSEs and PDSs as directories. However, as discussed in Directories and Directory Access, DFM does not provide full directory support. Also, ambiguities might arise if a PDSE or PDS name matches a prefix name. For example, you may have a PDSE named IBMUSER.DATA and a sequential file named IBMUSER.DATA.SAMFILE.

Therefore, the following rules are provided to help you control PDSE and PDS member access. These examples assume that the user ID is IBMUSER. Note that rules 1 and 2 take precedence over any of the other rules.

1. A DFMDRIVE ASSIGN specifying a PDSE or PDS implies that all the subsequent file references for that drive will be to members until a change directory (CD) command is issued, in which case see rule 2 (except that RENAME requires the full z/OS® path name).
2. A change directory into a PDSE or PDS implies that the file names that follow will be members. For example, CD "IBMUSER.MYDIR" implies that a reference to file A will be to member A of PDSE or PDS "IBMUSER.MYDIR" (except that RENAME requires the full z/OS path name).
3. Explicit usage of parentheses in a fully qualified name implies a member. For example, "IBMUSER.MYDIR(A)" refers to member A of the PDSE or PDS "IBMUSER.MYDIR".
4. A file name with a "\" preceding the last qualifier implies a member. For example, "IBMUSER.A.B\C" refers to member C of the PDSE or PDS "IBMUSER.A.B" (except that RENAME requires the full z/OS path name with parentheses around the member name).
5. A file name with a "." preceding the last qualifier implies a nonmember. For example, "IBMUSER.A.B.C" refers to a file named "IBMUSER.A.B.C".