Hello @Jay May,

This is one of the 27 municipalities in Belgium with special rules (i.e. the "faciliteiten", as in the link provided by Jakka).

This is a legislation that stipulates that communications between citizens and authorities can also be made in the minority language.  In most of those municipalities, street signs show both languages.

There have been many discussions in the past about how to properly reflect this in OSM.  If we use the bilingual form on the "name" tag of streets, then the address on every building must match the same form, which is already controversial (https://www.openstreetmap.org/changeset/137405959).  And how about the name of the town halls, police stations, train stations, social care and more?  Delicate issues need sensitive handling, as any choice here can be (mis)interpreted as if we were taking a political stance.  I am afraid the current consensus within the local community of mappers diverges from the notion that these municipalities should be considered as fully bilingual territories.

I am happy to announce we started a new discussion today with the purpose of clarifying or unifying the naming rules in those areas.  We agree that current mapping practice differs and contains inconsistencies.  We would gladly appreciate if you would please pause those edits in Belgium for a while, we are trying to reach a consensus about this delicate topic.

Thanks.