User exit 10 is only called up

if the FI document should be distributed by ALE.
The system identifies this by system indicator E_DISTRIBUTE = 'X' being set.
In function module FI_IDOC_PREPARE, system indicator E_DISTRIBUTE is active if ALE is active for message types FIDCC1 or FIDCC2.
With FIDCC1, it is also still possible at this point to prevent the document being distributed via user exit 003 (indicator NO_DISTRIBUTION = 'X').In this case, system indicator E_DISTRIBUTE is inactive and user exit 10 is not called up.
For message types FIDCC1 and FIDCC2,
if there is at least one clearable item in the document:
BSEG-XOPVW = 'X' (open item management)
or
BSEG-KOART = 'D'/'K' (customer/vendor).

If the three points mentioned above apply, the system calls active user exit 10 and transfers the entire FI document (BKPF, BSEG) as a document copy at to user exit 10.