Field help (ATCKFCY) 

A reciprocal account must be set up by pair of sites (accounting establishments).
Indicate in this field the site associated with the account in the same line in the grid.
The order of setup is of no importance.
This field is optional for the first line. The first line can be left blank at the site 1 and 2 level however a link account will be associated with them. All the companies using the chart code with a ledger ticked Balance/site, by default all the combinations of their financial sites will use the same link account of this line. All the combinations site 1/site 2 of the above lines will be considered as exceptions of this first line.