This can sometimes be a challenge with OSM, if the way you want to structure data doesn’t align with the way the community has decided to structure data.

I was looking into building a canoeing map based on OSM data. An important thing to map is “is a particular stream between two lakes navigable by canoe?” OSM has a defined canoe=yes/no tag, but it’s supposed to be used for legal access, not navigability.

In the place I wanted to map, canoeing is basally legal everywhere, but there are many streams that no one ever canoes down, because it would be an enormous pain. There isn’t a way to represent this is OSM today, and community tends to be resistant to adding tags that map “subjective” data.

The solution would probably be for me to keep my own database of navigable streams with references to the OSM features, except that OSM features don’t really have stable ids. If another mapper comes along and decides to map an existing stream in more detail, they might choose to delete an existing stream feature and replace it, split it up into multiple features, or join several existing features together — all of which will result in id changes.