Yesterday on The Postcode Anywhere blog Guy Mucklow wrote a nice piece called University Challenge. The blog post is about challenges with shared addresses and a remedy at least for addresses in the United Kingdom.
And sure, I also had my challenges with a shared address in the UK as reported in the post Multi-Occupancy.
But I guess the University Challenge is a universal challenge.
The postal formats and available reference data sources are of course very different around. Below is an example from the iDQ™ (instant Data Quality) tool when handling a Danish address with multiple flats. Here the tool continuously display what options is available to make the address unique: