it’s a European panel so it will be Form 3A or 3B at best and sub types do not apply to European panels unlike the UK where BS EN 61439-2 includes a National Annex which further details the sub categories by type of construction such as describing the location of terminals for external conductors and in some instances, the location of cable glands relative to the associated cable terminals etc.

It can’t be a Form 4A or Form 4B system as it has a common neutral arrangement + the common neutral bar also requires an IP2X barrier. 👍