diff --git a/browser/js/scatterPlot.js b/browser/js/scatterPlot.js
index 858f597cfce3d8eafa7fcb3134bd6829ef87af35..8e9b019ca8a79e6e7db31b6c8011b16a0e5d787b 100644
--- a/browser/js/scatterPlot.js
+++ b/browser/js/scatterPlot.js
@@ -1648,6 +1648,7 @@ ScatterPlot.prototype = {
             .remove();
         leg.on("click", function(d){
             if (self.mode !="bar"){
+                // Multi-selection by clicking on a legend
                 if (!d3.event.ctrlKey) 
                     self.m.unselectAll()
                 var listToSelect = [];