XOVER [range]

    The XOVER command returns information from the overview
    database for the article(s) specified. This command was
    originally suggested as part of the OVERVIEW work described
    in "The Design of a Common Newsgroup Overview Database for
    Newsreaders" by Geoff Collyer. This document is distributed
    in the Cnews distribution.

    The optional range argument may be any of the following:
                an article number
                an article number followed by a dash to indicate
                   all following
                an article number followed by a dash followed by
                   another article number

    If no argument is specified, then information from the
    current article is displayed. Successful responses start
    with a 224 response followed by the overview information
    for all matched messages. Once the output is complete, a
    period is sent on a line by itself. If no argument is
    specified, the information for the current article is
    returned.  A news group must have been selected earlier,
    else a 412 error response is returned. If no articles are
    in the range specified, a 420 error response is returned
    by the server. A 502 response will be returned if the
    client only has permission to transfer articles.

    Each line of output will be formatted with the article number,
    followed by each of the headers in the overview database or the
    article itself (when the data is not available in the overview
    database) for that article separated by a tab character.  The
    sequence of fields must be in this order: subject, author,
    date, message-id, references, byte count, and line count. Other
    optional fields may follow line count. Other optional fields may
    follow line count. These fields are specified by examining the
    response to the LIST OVERVIEW.FMT command. Where no data exists,
    a null field must be provided (i.e. the output will have two tab
    characters adjacent to each other). Servers should not output
    fields for articles that have been removed since the XOVER database
    was created.

    The LIST OVERVIEW.FMT command should be implemented if XOVER
    is implemented. A client can use LIST OVERVIEW.FMT to determine
    what optional fields  and in which order all fields will be
    supplied by the XOVER command. See Section 2.1.7 for more
    details about the LIST OVERVIEW.FMT command.

    Note that any tab and end-of-line characters in any header
    data that is returned will be converted to a space character.

2.8.1 Responses

      224 Overview information follows
      412 No news group current selected
      420 No article(s) selected
      502 no permission