F07901 Custom Records

I would like to know, when inquiring on F07901 using P07901, and that entries corresponding to the search criteria are displayed, what triggers the green checkmark in the grid under the "Custom Record" column. I can see that when adding a record in F07901, on the P07901/W07901F form, the "Custom Record" checkbox is checked by default, that is fine, but in what field of what table does JDE stores that indication? Because when displaying records from the F07901 where the green checkmark is displayed for custom records, the table read is the F07901 and I see no field on