The Store Unique (STOU) feature allows you to control how file
    version numbers are treated when you copy (PUT) files from
    local to remote hosts. After connecting to the remote host, you
    toggle the Store Unique feature on and off by issuing the sunique
    command at the FTP prompt, as follows:

     FTP> sunique
     Store unique on.
     FTP> sunique
     Store unique off.
     FTP> sunique
     Store unique on.

    The Store Unique feature behaves differently when copying files
    between OpenVMS and UNIX. It also behaves differently if you use
    wildcards or specify version numbers.

    The following table shows the results when you copy the file
    text.txt from OpenVMS to UNIX.

                  File
                  test.txt
                  Exists     Store
                  on UNIX    Unique
    FTP Command   System     On        Store Unique Off

    FTP> PUT      No         text.txt  text.txt
    text.txt
    FTP> PUT      Yes        text.txt.1 text.txt
    text.txt

    The next table shows the results when you copy the file
    text.txt;* from OpenVMS to UNIX.

                  Files
                  test.txt.1
                  test.txt.2
                  Exist on   Store
                  UNIX       Unique
    FTP Command   System     On        Store Unique Off

    FTP> PUT      No         text.txt.2 text.txt.2
    text.txt;*                         text.txt.1
                             text.txt.1

    FTP> PUT      Yes        text.txt.2text.txt.2
    text.txt;*                         text.txt.1
                             text.txt.1.1