diff --git a/doc/backlog.md b/doc/backlog.md
index da6d3e5..c07e849 100644
--- a/doc/backlog.md
+++ b/doc/backlog.md
@@ -31,6 +31,7 @@
 - Does data autofitting work when changing dashboard variables?
 - Rename request parameters from "request_" to "__request"
 - Add "maxZoomLevel" option to accompany the "FitToData" option
+- Add https://github.com/mlevans/leaflet-hash as location picker
 
 ## Documentation
 - Note about installation
diff --git a/doc/wms.rst b/doc/wms.rst
new file mode 100644
index 0000000..31bf6ba
--- /dev/null
+++ b/doc/wms.rst
@@ -0,0 +1,138 @@
+################################
+WMS layers, sources and features
+################################
+
+
+*****
+About
+*****
+`leaflet.wms`_ is a Leaflet plugin for working with Web Map services.
+It provides single-tiled, untiled and non-tiled layers, shared WMS
+sources, and ``GetFeatureInfo``-powered identify.
+
+- http://heigeo.github.io/leaflet.wms/
+- https://github.com/heigeo/leaflet.wms
+
+.. _leaflet.wms: https://github.com/heigeo/leaflet.wms
+
+
+This work has been supported by the Flanders Environment Agency (VMM)
+on behalf of the CORONA-EU project.
+
+http://shiny.irceline.be/examples/
+
+
+***********************
+IRCELINE RIOIFDM layers
+***********************
+
+About
+=====
+Display multiple WMS layers from http://geo.irceline.be/wms.
+
+- https://source.irceline.be/corona-eu/opendataviewer/blob/master/requirements.md
+- https://source.irceline.be/corona-eu/opendataviewer/blob/master/geo.irceline.be/www/pm25_anmean_rioifdm_EN.html#L68-87
+
+Analysis
+========
+The list of layer prefix labels is ``bc``, ``no2``, ``pm10`` and ``pm25``.
+
+
+``leaflet.wms`` snippets
+========================
+
+Tile layer
+----------
+https://github.com/heigeo/leaflet.wms#lwmstilelayer
+::
+
+    var pm25_rioifdm = L.tileLayer.wms("http://geo.irceline.be/rioifdm/wms", {
+            layers: 'rioifdm:pm25_anmean_2017_atmostreet_vl',
+        transparent: true,
+        format: 'image/png',
+            tiled: true,
+        opacity: 0.7,
+        maxZoom: 19
+    });
+
+    var layers_rioifdm_anmean = new L.Control.Layers({
+            "Fijn stof PM<sub>10</sub> interpolatie 2017": pm10_rioifdm,
+            "Fijn stof PM<sub>2,5</sub> interpolatie 2017": pm25_rioifdm,
+            "Stikstofdioxide (NO<sub>2</sub>) interpolatie 2017": no2_rioifdm,
+            "Black Carbon (BC) interpolatie 2017": bc_rioifdm
+        }, null, {collapsed: true, position: 'topright'}).addTo(map);
+
+::
+
+    map.removeLayer(pm25_rioifdm);
+
+
+Legend
+------
+::
+
+    var rioifdmLegend_PM25 = L.control({position: 'bottomleft'});
+    rioifdmLegend_PM25.onAdd = function (map) {
+    var div = L.DomUtil.create('div', 'info scale');
+        div.innerHTML +=
+        '<img src="https://www.irceline.be/air/legend/pm25_anmean_EN.svg" style="background-color:rgba(255,255,255,0.75);" alt="legend" >';
+    return div;
+    };
+
+    rioifdmLegend_PM25.addTo(map);
+    map.removeControl(rioifdmLegend_PM25);
+
+
+Stations
+--------
+https://github.com/heigeo/leaflet.wms#lwmssource
+::
+
+    var source = L.WMS.source("http://geo.irceline.be/annual/wms", {
+            transparent: true,
+            cql_filter: "network = 'Flanders'",
+            format: 'image/png',
+            tiled: true,
+            opacity: 0.7,
+            info_format: 'text/html',
+            time: '2017'
+    });
+    var bc_station_anmean = source.getLayer("bc_anmean_station");
+    var no2_station_anmean = source.getLayer("no2_anmean_station").addTo(map);
+    var pm10_station_anmean = source.getLayer("pm10_anmean_station");
+    var pm25_station_anmean = source.getLayer("pm25_anmean_station");
+
+
+All at once
+-----------
+https://source.irceline.be/corona-eu/opendataviewer/blob/master/geo.irceline.be/www/pm25_anmean_rioifdm_EN.html#L68-87
+::
+
+    var source = L.WMS.source("http://geo.irceline.be/annual/wms", {
+        transparent: true,
+            format: 'image/png',
+            opacity: 0.7,
+            info_format: 'text/html',
+            time: showYear
+    });
+
+    var pm25_station_anmean = source.getLayer("annual:pm25_anmean_station").addTo(map);
+
+    var pm25_rioifdm = L.tileLayer.wms("http://geo.irceline.be/rioifdm/wms", {
+            layers: 'rioifdm:pm25_anmean_'+showYear,
+        transparent: true,
+        format: 'image/png',
+        opacity: 0.7,
+        maxZoom: 19
+    }).addTo(map);
+
+    var layers_pm25_anmean = new L.Control.Layers(null, {
+            "Annual mean (interpolated)": pm25_rioifdm,
+            "Measured annual mean": pm25_station_anmean
+        }, {collapsed: false, position: 'topright'});
+
+    map.addControl(layers_pm25_anmean);
+
+
+    L.control.attribution({position: 'bottomleft'}).addTo(map);
+    map.attributionControl.setPrefix('&copy; <a href="http://www.irceline.be/" target="_blank">IRCEL - CELINE</a> | &copy; <a href="https://vito.be" target="_blank">VITO</a> | <a href="https://www.openstreetmap.org/copyright" target="_blank">OSM</a> | <a href="http://leafletjs.com/" target="_blank">Leaflet</a>');