For the Gouvernementstraat, that’s an interesting case
The street is half in Flanders, half in Brussels, which means it might need both the name:left/name:right tags, as well as the name:nl/name:fr tags.
If you look at CRAB , this road is called Gouvernementsweg. But the GRB also shows “Goevernementsweg” for this road, so I think this is the official (and wrong) Dutch name of the Brussels side of this street, which is also shown on the Urbis Dutch version. So you can’t just say “map the street signs”, you have to look at the street signs at the correct side of the street.
The convention for streets that have a different name on the left and right side is that the name tag should have both, separated by space hyphen space " - ". But this is also the convention for the French and Dutch name, so this is going to be confusing.
To further complicate it, Kraainem is a “faciliteitengemeente”, so the name should be in Dutch only, and the French name only added under name:fr (according to https://wiki.openstreetmap.org/wiki/Multilingual_names#Language_facilities)). Not that Kraainem is mapped like that, as that wiki page aknowledges, and massively changing this in the facility communities bordering Brussels should probably be discussed first on talk-be.
So given that Brussels is on the left (for the part I look at), we get:
and then we have:
name:left=Route Gouvernementale - Goevernementsweg (Dutch first allowed too)
name:right=Gouvernementsweg - Gouvernementsweg
And because why not
name:nl=Gouvernementsweg - Gouvernementsweg
And the name should be:
Route Gouvernementale - Goevernementsweg - Gouvernementsweg
But that doesn’t make very much sense, so maybe it would be better to do a combination of " - " and " / ".
I think I would opt for Route Gouvernementale - Goevernementsweg / Gouvernementsweg
I think that houses in Flanders, like this one: https://www.openstreetmap.org/way/189640119#map=19/50.82927/4.47094
are wrong in the sense that they should have Gouvernementsweg, the official Flemish spelling. It is also wrong in the sense that the French name should not come first. And maybe the French name should not be included in the name tag at all.
(EDIT: added name:left/right and name:nl/fr tags)