The /SUMMARY qualifier produces a summary report of the selected
    records. The report is directed to the current SYS$OUTPUT device,
    unless you use the /OUTPUT qualifier to write it to a file.

    Summary reports give statistical summaries of the resources
    specified by the /REPORT qualifier for each value of the summary
    key specified by the /SUMMARY qualifier. If you omit the /REPORT
    qualifier, the summary report gives the total number of records
    processed for each summary key value.

    The first line of the summary report shows the time span of the
    data processed (when the first and last records processed were
    logged in the input files), with a title in the middle. You can
    use the /TITLE qualifier to specify your own title.

    The next few lines of the report are column headings. There
    is one column for each summary_item, then one column for each
    resource specified by the /REPORT qualifier. The columns are laid
    out in the same left-to-right sequence as the equivalent keywords
    in the /SUMMARY and /REPORT qualifiers.

    The rest of the report uses one line for each summary key value.
    It gives a summary of the resources associated with that summary
    key value. The data is sorted in ascending order of the summary
    key value.

    See also the /BINARY qualifier, which copies the selected records
    to a file, and the /BRIEF and /FULL qualifiers, which produce
    brief and full reports of the selected records.

    You cannot use the /SUMMARY qualifier with the /BINARY, /BRIEF,
    or /FULL qualifiers.