I planned on drastically expanding the searchfields on some main datagrids but found out that it is not possble to search 0-1 references. E.g. an organisation has multiple addresses, and I would like to search for organisations that have a zipcode that contains '3223', is this not possible?
I see no technical problem in allowing 0-1 references in search fields. You can add it as a feature request and see how that pans out.