thank you ale. i guess i was specifically wondering whether the physical/non-physical tag difference matters for rendering in osm carto. in other words, do non-physical tagged items get rendered by osm carto? thank you.
To add to what alesarrett said, the “Since this is a non-physical tag” text has been in that page since 2008. My guess is that it’s a translation from German and the sense of the original hasn’t quite got carried over. In English the terms “top-level tag” or “primary tag” are probably more used.
I don’t think “physical tag” is a well-defined concept. However, you can loosely group OSM tag in two groups: those that indicate what something is, and those that provide additional information. For example,
tells us that there is a road here, but
just tells us that something is 4 meters wide, but not what it is. It is these two groups that are referred to as “physical” and “non-physical” in the text you linked.
is then a non-physical tag, because it tells us that something is used for a particular sport, but not what that something is.
This, almost by definition, means that objects with only non-physical tags are usually not rendered at all, because there is no way of knowing what they are.
“Physical tags” are sometimes also called “top-level tags”. I think I have seen “primary tags” too.
(Is there a list of physical/primary and non-physical/secondary tags? Unfortunately, no. You’ll have to read the documentation of each tag and figure out which group it belongs to.)