Flat or what?
From what I know, the equivalent of our YDYt-Żo or NYIF-J (stegleitungen) is allowed but with restrictions, i.e. allowed in dry rooms, can be laid only in plaster or under plaster, glued or on plastic handles. Cannot be stacked on flammable materials and in dry construction racks. In practice, no one uses it anymore. I haven't seen the Polish equivalent of YDYp or our cable manufactured for VDE.
Until now, I only met counters inside. In single-family buildings in the switchgear and multi-family buildings in the basement or on staircases. Cable connectors with protections also inside, right after the cable is introduced into the building or rarely in a box outside.
Aged but common cable connector:
Counters in a multi-family building:
Selective overcurrent protection (or fuses):
One-family houses:
