…
Everything below is read from the registry, the Coverage Tracker and the node read-API when this page loads, and the score from the Index pipeline's measured cells. Where a cell is empty it is empty, and the score says so: missing data weighs it down, and its label says whether it is complete, partial or simulated.
- the region is as far up as the adding goes
The interactive map requires network access and JavaScript. Leaflet 1.9.4 and the OpenStreetMap basemap load from CDN. The scale ladder and the reading card on this page still describe each scale without it.
The nested outlines are one drawn worked example of the nesting rule, not a boundary for any city. Markers are placed from data/coordinates.json; cities with no coordinates are named below the map rather than dropped from it. Every city with coordinates is a marker; the nested outlines are one drawn example. Every outline here is hand-drawn and rough: it teaches the nesting rule, it does not claim real borders. The point is the same one every page makes: three levels add up, two are only read, and the iron line in the ladder is where that difference sits.
↪ How the levels add up, as a diagram: how a score adds up, the scale-by-scale walk, and the aggregation rules.