I was updating my old high school on OSM and noticed that whoever mapped it before used a multipolygon to map the buildings. From what I can tell the benefit to this is that you can map more complex shapes by having them be related, is that correct?2
There are some buildings that have been added as building=yes instead of building=school (some haven't been marked at all) and I want to make sure I understand it better before I go and make any big changes.
EDIT:
Some extra clarification as to why I'm asking. There are some buildings that have been added as separate multipolygons which don't make sense to me. (see screenshot), these two buildings were added as separate multipolygons but they are connected and form part of the same building.
I also get a warning in JOSM that says "amenity inside amenity - amenity=school inside amenity=school"
I work at a university (grande école) where the buildings are mapped like this. Despite being one large structure, it was not always the case. Building A and C were built in the 90s, building B in the early 2000s was built to connect them. We still use the different building names today and have A through H. D is a castle and F was only added last year, even though G and H are nearly as old as A and C. I feel bad for the amphitheatre being left out of the lettered naming scheme... Poor "AMPHI".
Perhaps your school was built building by building so they just added a new polygon instead of redrawing it.