Look for orphan nodes

[robsavoye]

The data validation in Underpass should be extended to look for orphan nodes in the osmchange file. Orphan nodes are nodes with no tags and not part of a way.

[mmd-osm]

This definition seems a bit incomplete. Nodes without tags might still be used in relations, such as https://www.openstreetmap.org/node/5726500366 as part of https://www.openstreetmap.org/relation/8415506

[robsavoye]

Sure, and since the data is limited to what's in the osmchange file, it's not always possible to determine if a new node is part of an existing way. This was a requested feature, so this issue is mostly a placeholder so it doesn't get lost. This description should be extended to relations in addition to ways.

[mmd-osm]

Minutely diffs are not really suitable for analytical use cases. You'd always have to process them alongside your local planet database and perform database lookups as needed. That's probably not an issue as long as people are only adding new buildings. Beyond that you're running into all sorts of issues.