You must use stream mode (MODE S) and file structure (STRUCT F) when transferring files in the root, QOpenSys, QDLS, and QOPT file systems.
Root, QOpenSys, QDLS, and QOPT files can exist in any valid code page.
Data conversion and CCSID assignments vary depending on the transfer TYPE used. You might want to refer to the CCSID code page tagging for i5/OS® files.
When appending data to an existing file, the CCSID tag of that file is not changed. When appending data to an existing file using TYPE A, the data is converted to the code page of that file.