To write a disk-format SAS file, you usually need only to specify the two-level filename in the appropriate SAS statement. That is, in most cases you do not need to assign a libref to the file because ...

Note: If you are writing SAS files to tape with the TAPE engine, you must mount the tape as a labeled Files-11 tape. A labeled Files-11 tape has header information preceding each file. An unlabeled, ...