Hello,

I wish to inform you that in Belgium we never repeat postcodes or city names on every possible address or POI.  This is because we successfully drew all the postcode areas; this also provides a safer system than relying on every mapper to guess the full address.  (Yes, in this country some areas have strange shape and people can easily get this wrong; we chose this system as a response to massive data corruption.)

See an example here: every point within this area is automatically understood has having postcode 1000, this is the reason why we don't repeat it.
https://www.openstreetmap.org/relation/3379410

Happy mapping.