Contacts sorting is not completely defined

QContactSortOrder allows sorting over any detail. However, the order when filtering on a multi valued detail (say, QContactPhoneNumber::PhoneNumber) is not defined. Looking at the code, it appears mobility uses the QContactDetail::detail<DefinitionName>() method, which fetches the first detail available. The order of the details returned by QContact::details() is not defined, so sorting can't be reliable on multi valued details.