I don't know what everyone means when they use 'rule' in the title and at this point I'm too afraid to ask. Please enlighten me.
In the Netherlands I saw some building were, instead of having a street number-flat number, the building had all the numbers listed on them. So, if the building had 100 houses, the street number for the building would be 150-249, and the next street number would be 250.
It's possible they had a similar system.