diff --git a/lib/renderer.js b/lib/renderer.js
index <HASH>..<HASH> 100644
--- a/lib/renderer.js
+++ b/lib/renderer.js
@@ -111,6 +111,19 @@ var renderPath = {
     'MultiPolygon': function(mp) {
         mp.forEach(renderPath.Polygon, this);
     },
+    /**
+     *  NOTE: RENDERING POLYGONS WITH HOLES
+     *  Canvas appears to use the "ESRI Polygon" convention:
+     *
+     *  The ESRI polygon is an array of rings and an inner ring, or hole, 
+     *  is specified by ordering the points counter-clockwise. 
+     *  
+     *  Alternative, the GeoJSON polygon is an array of rings, but the first 
+     *  is always the outer ring and the following ones are inner rings.
+     *
+     *  Creating polygons with holes that follow the ESRI Polygon convention
+     *  magically seems to work with Node-Canvas/Cairo. Weird.
+     */
     'Polygon': function(p) {
         p.forEach(renderPath.LineString, this);
     },
Added a note in the renderer about Polygons with Holes