With one exception, the positional parameters in a mailing list
    specification provide alternate addresses to which certain sorts
    of list related activity should be directed (e.g., an address
    to which errors should be sent to rather than back to the list
    itself).

    The positional parameters are so named for a reason: their
    position in the comma separated list distinguishes which
    parameter is being specified. When more than one parameter
    (positional or otherwise) is specified, they must be separated
    by commas. If you want to specify a positional parameter but
    omit some which come first, then specify asterisks, *, for the
    positional parameters which you want to omit. For example,

 db> add foo-list "<d1:[sue]sample.dis, *, *, sue@example.com"

    Finally, to make the use of a positional parameter conditional,
    end the parameter value with an asterisk. In this case the
    value associated with the parameter will only be used if the
    corresponding message header line is not present in the message
    being posted to the list. (The asterisk will not appear in the
    message header should the parameter take effect.)

    Without further ado, the positional parameters are:

 error-return-address

    ERROR-RETURN-ADDRESS specifies an address to replace the
    message's regular envelope From: address as well as an address
    to be inserted into the header as an Errors-to: address. This
    header line is not generated if this address is not specified.

 reply-to-address

    The REPLY-TO-ADDRESS parameter specifies an address to be used as
    a Reply-to: address.

 errors-to-address

    The ERRORS-TO-ADDRESS parameter specifies an address to be placed
    on the Errors-to: header, if this address should be different
    from the ERROR-RETURN-ADDRESS that is used as the envelope From:
    address.

 warnings-to-address

    The WARNINGS-TO-ADDRESS parameter specifies an address to be
    placed on the Warnings-to: header line. This header line is not
    generated if this address is not specified.

 comments

    The COMMENTS parameter specifies a string to be placed in a
    Comments: header line. This header line will add to any Comments:
    header lines already present in the message being posted to the
    list.