/CONFIRM
       /NOCONFIRM (default)

    Controls whether a request is issued before each purge operation
    to confirm that the operation should be performed on that file.
    The following responses are valid:

    YES      NO       QUIT
    TRUE     FALSE    Ctrl/Z
    1        0        ALL
             <Return>

    You can use any combination of uppercase and lowercase letters
    for word responses. Word responses can be abbreviated to one or
    more letters (for example, T, TR, or TRU for TRUE), but these
    abbreviations must be unique. Affirmative answers are YES, TRUE,
    and 1. Negative answers include: NO, FALSE, 0, and pressing
    Return. Entering QUIT or pressing Ctrl/Z indicates that you want
    to stop processing the command at that point. When you respond by
    entering ALL, the command continues to process, but no further
    prompts are given. If you type a response other than one of
    those in the list, DCL issues an error message and redisplays
    the prompt.