Reading a pretty long discussion of tagging the Holocaust memorial in Berlin, it surprises me, how unclear our Wiki documentation still is. The main controversy there is about (not) using building=* tags for individual parts of the memorial installation. For those, who are not familiar with this memorial, it mainly consists of rectangular monoliths (stelae) of different height, arranged in rows.

It has been mentioned in that discussion, that current convention about a qualifying feature for using building=* is a presence of room inside the structure (I’d add, that it also applies to “parent structure”, since we still have building=entrance in use), so people can come in and stay inside it, and it’s the purpose of this structure.

Sometimes, it could be an extreme case, like building=roof, where we usually have an open space under the roof instead of an isolated space, forming a room. But unfortunately, both Buildings article and Key:building have almost zero information on this particular topic.

I mean, come on, guys, building=* is among the top tags by usage and it is often misused, but there is no more or less clear definition of it in English documentation. In Russian documentation, due to widespread legal nihilism, we have the first paragraph of the RU:Здания (Russian version of Buildings article) that gives a definition of the term “building” for awhile. German article has a bit shorter explanation as well. English version says something about a couple of special cases (houseboats, for example), but gives no general picture, like if it were obvious. No, it is not, especially in OSM, where terms quite often have own special meaning and definition.

Personally, I don’t see any issue with adding something like that to the English article by myself, except I’m obviously not a native English speaker and my English is American (I had an experience of complaints from a couple of Britons regarding of that).

I think, it is important to tell about the qualifying features and about the fact that building=* does not really create a contradiction with man_made=* because, for example, large TV transmission towers or lighthouses often have pretty much space inside, and it is intended to be a workspace for people.

Getting back to the Holocaust memorial, obviously, those stelae are neither buildings nor man-made structures in terms of current tagging schemes. These are historic=memorial memorial=stele or, better, historic=memorial memorial:type=stele objects, while there is still no definite way to tag complex memorial installations in details. Personally, I’d propose something like using historic=memorial for the whole boundary of memorial and corresponding memorial:type=* for the outlines of each particular part of it, since there are memorial complices consisting of multiple stelae, statues, plaques and obelisks within a certain boundary.