Only for the record, in Italy the modularity is a de facto standard since some 40 years +. When you build a new house the initial question is only whether and

Only for the record, in Italy the modularity is a de facto standard since some 40 years +. When you build a new house the initial question is only whether and where you want "503" or "504" boxes in the walls, they are corresponding to 3 modules and 4 modules and are ubiquitous, much later you may decide which make/model of switches, sockets etc. to populate them. The Italian sockets are 1 module, Din/Schuko are 2 modules, switches and push buttons, etc. are 1 module. Till a few years ago you only used 503's, nowadays the trend is towards 504's, at least on the "low" boxes (where you normally have sockets). There are 4 or 5 reknown manufacturers, each with more than one "series" of switches/sockets/etc. with different designs. Some few more details about sockets: https://news.ycombinator.com/item?id=27652337 https://news.ycombinator.com/item?id=27652337