{map} draws countries filled by a value of their row - a choropleth - as inline SVG on the server (tags/_lib/map.php), from Natural Earth's outlines kept in PAD itself: no JavaScript, no map tiles, no remote service. The first parameter picks the view: the whole world, or a crop of the same projection at full detail for a continent. An unknown view is an error under the strict check.

The rows come from data= as for {chart}, or from the content of the pair - JSON, YAML, XML or CSV, read before the level walks it. key names the country, written as an alpha-2 code (NL), an alpha-3 code (NLD) or the English name; value the number. Rows of one country add up. A key that is no country is not drawn but named in the title (not on the map: ...), so a typo shows instead of disappearing.

The values are put in seven colour steps - the heatmap's --pad-chart-heat-0 to -6 - with a scale under the map. scale='linear' spaces the steps evenly between the lowest and highest value; scale='quantile' gives each step the same number of countries, which keeps a few very large values from washing out the rest. A country without a value is --pad-map-empty, and a map without any data is drawn all in grey.

Every country has a <title> - Netherlands: 1,234, the tooltip on hover - and the <desc> lists the values for a screen reader. Countries too small to keep an outline at the scale drawn are shown as small diamonds. For a single flag, see {country}.