EVENT
The event is executed prior to displaying the open items. Thecustomer-specific fields of structure CI_RFOPS (which is included instructure RFOPS / RFOPS_S) can be filled.

INTERFACE
The list of selected items (T_POSTAB) and the document headers (T_BKPF)are passed to the add-on component for informational purposes only. Thisdata must not be processed. Instead, an additional empty table(T_POSTABSUB) is passed. This table must be built in the add-oncomponent with the contents of the fields that are substitutable. TheTABIX field contains a row number that indicates from which row inT_POSTAB the field contents originate. If multiple add-on components usethis event and, when doing so, these components fill different fields ofstructure RFOPS_S, you need to transfer all customer-specific fieldsfrom T_POSTAB to table T_POSTABSUB. This can be done with themove-corresponding command (see below).
SAP reserves the right to extend the structures RFOPS and RFOPS_S usingappends or includes (SI_INCLUDE).
ERP05: Interface extended with optional parameter I_RF05A

Example
You want to substitute the contents of the customer field ZZTEST withthe content 'TEST' in all rows of table T_POSTAB. For the most part,this requires a command sequence like this:
loop at t_postab.
t_postabsub-tabix = sy-tabix.
move-corresponding t_postab to t_postabsub. "initialize fields ofCI_RFOPS
t_postabsub-ZZTEST = 'TEST'.
insert t_postabsub index sy-tabix.
endloop.
Make sure you write this code in your own module!