7.1: Error codes in BAPI Wrappers

this relates to NW Mobile 7.1, SP04

Can anybody point me to some documentation, what kinds of errors should be set in the BAPI Wrapper?

my observations:

If a consistency check in the backend fails, my BAPI Wrapper returns 'E' in the BAPIRETURN2 structure, the change is discarded on the client.

How can I handle that on the client? I vaguely remember that there are some Listeners, but I could not find documentation on that.

Thanks, Andre