The DIRECTORY command is used to show the currently queued
    message files in either all channel queues or a particular
    channel queue. In the listing, message identification numbers
    will appear to the left of each message file name. These numbers
    may be used with the DELETE, HISTORY, HOLD, READ, RELEASE, and
    RETURN commands so as to identify which message to operate on.

    The DIRECTORY command produces its listing by looking at either
    the actual queue directory tree on disk, or by looking at
    the queue cache database. Use either the VIEW command or the
    /DIRECTORY_TREE or /DATABASE qualifiers to control the source
    of information used. Note that when /DIRECTORY_TREE or VIEW
    DIRECTORY_TREE is used, the "queued since" dates are the date
    and time that the message file was created; when /DATABASE or
    VIEW DATABASE is used, the queued since dates are the date and
    time that the message was enqueued and may pre-date the actual
    creation date for the message file itself.