Positional_Parameters

   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.