I really like the idea of intentional loopholes. It is a great way ton conceptualize what I have been doing for a long time.
In my opinion there is a certain feeling of satisfcation when feeling like the domain is modeled completely. Uncertainty or loopholes leave an itch to scratch. That's why people insist on modelling addresses.
Adresses which are a fundamentally easy thing, should be easy to model.
Like what, a house is on a street, has a number a city a state and a postcode. All of them are obviously required. And then you get into actual addresses. People who live in a village without a street. Some countries have no states. Some names can be extremely long. For example my condo adresss is 62 characters alone.
I think the only thing you can rely on for addresses is postcode, city and the rest is free form. But that feels so unsatisfactory.
Addresses are hard. Off the top of my head: I live in Germany. Germany has states, but they are not part of postal addresses. A lot of US sites keep insisting on entering a state wven though that is wrong. There are tiny villages without street names. The name of the village substitutes for the street name. Maybe there are single house settlements with house numbers - I am not sure.
And then there is Mannheim, a city with no street names. This was originally a planned city where the city center has rectangular blocks numbered in a letter-number scheme. So there is e.g. a block L5. This refers to one side of the 4 adjacent streets. The other side of these streets is addreseed with L3, L5, etc... what his means is that you have addresss like O7 6 - a single letter and two numbers in a row. I bet that a lot if input validators for addresses trip over something like that.
