Trying to understand expression in SQL module

[Kenroy]

Hello everyone,
    I am  reading the  sql model query config trying to understand it. I
came across the following an expression  *${....acct_table1}*  . What is
the purpose of the the ellipsis (....)  in front of the  variable
acct_table1.


See below for full query expression.


INSERT INTO* ${....acct_table1}* \
(${...column_list}) \
VALUES(\
'%{Acct-Session-Id}', \
'%{Acct-Unique-Session-Id}', \
'%{SQL-User-Name}', \
NULLIF('%{Realm}', ''), \
'%{%{NAS-IPv6-Address}:-%{NAS-IP-Address}}', \
NULLIF('%{%{NAS-Port-ID}:-%{NAS-Port}}', ''), \
'%{NAS-Port-Type}', \
TO_TIMESTAMP(%{integer:Event-Timestamp}), \
TO_TIMESTAMP(%{integer:Event-Timestamp}), \
NULL, \
0, \
'%{Acct-Authentic}', \
'%{Connect-Info}', \
NULL, \
0, \
0, \
'%{Called-Station-Id}', \
'%{Calling-Station-Id}', \
NULL, \
'%{Service-Type}', \
'%{Framed-Protocol}', \
NULLIF('%{Framed-IP-Address}', '')::inet), \
                                        '%{Nomadix-User-Definable-1}', \
                                        '%{Nomadix-User-Definable-2}', \
                                        '%{NAS-Identifier}' "