There are problems with level=* tag stemming from the fact that not all mappers agree on what it means. This problem comes up more often in some geographic areas than in others where different floor numbering traditions exist. In this sense it is like name=* tag where certain parts of a name stop looking like parts of a name after being translated into a different language.
So what are exactly the problems with level=*? Some people think that the value of this tag should be whatever floor number that is used in place. You can usually but not always read it off some plaque, floor plan or elevator button. Other people think that the value should be a number such that the first floor at or above the ground level gets number 0, the floor above it gets 1 and so on. Those two different ways of assigning a value could be exactly the same, especially for English-speaking areas where they have a “ground floor” as level=0 and a “first floor” as level=1. If you are from those places, you may not even understand that there’s a problem. If you are from a place like Russia or the US, it’s evident for you that those ways are different. I’ll be using Russia as an example because it’s where I map.
But there should be no debate about the exact definition of level=* tag because we have a wiki where it’s perfectly documented, right? Not quite. First of all, we don’t have one wiki, we have multiple wikis in different languages. Those languages may correspond to areas with different floor numbering traditions, which in turn affects the wiki contents. Again, this is like name=*, where local wiki editors put their preferred spin on what should and what should not be part of a name.

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