Use of Book Code Chartfield

We would like to hear how other companies use the Book Code Chartfield. Do you have your foreign subsidiary companies sending the central Finance team a trial balance in local currency? If so, and you do use book code, how does the foreign subsidiary company’s trial balance get processed in PS? What book code is used for their journals?

At our company, we have a book code called COMN to represent entries that are common across all companies, and if a journal is needed to get to IFRS accounting basis, we would use a book code called IFRS as incremental adjustment. Then, the total of COMN + IFRS would get to the IFRS accounting basis.

With this configuration, our challenge is that the foreign subsidiary is sending us their trial balance and it's all IFRS basis. So, how would we record the incremental adjustments?

Please share with us how you have configured the Book Code Chartfield and especially how the foreign companies enter their journals in PS GL. Thanks!