Hello,

This is (literally) your first day editing OpenStreetMap and you a trying to impose personal views on how the database should be structured, not hearing to objections from users who have been mapping for years.

OSM is a geographical database.
We do not repeat the same information on every possible node.

Like several European countries, we have successfully integrated all the postcodes and municipalities in OSM, and the available reverse geocoders already automatically get this information.

Post code 1000 is here: https://www.openstreetmap.org/relation/3379410  Every object inside this area is automatically recognised as having this post code.

Brussels-City is here: https://www.openstreetmap.org/relation/58274  Same logic.

Please do not add duplicate information.  Help us keep a clean database.

Thanks.  Have a nice day.