Hi Peter,

I’m really pleased to see this as it’s a feature I’ve been thinking about for years, and pretty much the solution I had in mind so it’s great to see you having the stamina to carry it this far. I missed the forum discussion so I’m going to make a few suggestions here.

For the terms for parts of embankments, I suggest

• top_edge, as crest can mean the top surface and top_edge is generalisable to cliffs, earth banks, dams, cuttings etc.
• face, although slope is reasonably clear I think face is more correct, it’s generalisable, and you may want to save slope for lines of maximum slope that join top to bottom in some distant future.
• toe, I think it’s good as it is.

While I totally agree about using the form man_made=embankment:toe and man_made=embankment:slope (or face), I don’t think you should propose the synonym man_made=embankment:crest (or top_edge), because as embankments get mapped this way it will break unaware data consumers / renderers, which the rest of the proposal doesn’t do. If it’s necessary to clarify it really is the top edge that has been mapped, why not use

• man_made=embankment, and
• top_edge=yes

Also, the distinction between mapping the slope/face as a closed way or multipolygon seems like a matter of mapping style to me, and either way would work but some mappers will prefer one method over the other. Either way you end up with an area with the same tag, with some nodes shared with the top_edge and toe lines. Personally I would only make multipolygons a suggested way of mapping rather than integral to the proposal.

Good luck, and please post updates here and on the forum.

Wow! Thank you for taking the time to think all of this through and conduct such a detailed analysis. Am I reading your diagram correctly that almost everything tagged as wetland or marsh in OSM is considered improved grassland (B.4) in the Phase 1 data? I’m trying to figure out if that can be squared? I can see how B.5 marshy grassland would be tagged this way… I suppose you can get muddy parts of fields that are also grassy?