When entering a search for a particular record e.g.
the 'Business Partner info' screen after selecting the
Business Partner field in a Request, you can search by
Key, name , contact , Zip, Phone. Often an existing
customer record will contain incomplete data fields, so if
you enter more than one criteria and one of them
happens to be blank on the existing record - the search
will not locate those details. This will lead you to
conclude that a new record should be created.
I think the rule as it stands is a search for: x and y and
perhaps it would be more useful and desirable if it was
search for: x or y scenario.