diff --git a/documentation/src/state/routing.js b/documentation/src/state/routing.js
index <HASH>..<HASH> 100644
--- a/documentation/src/state/routing.js
+++ b/documentation/src/state/routing.js
@@ -1,5 +1,12 @@
 export const LOCATION_CHANGE = 'LOCATION_CHANGE';
 
+/**
+ * This is a simple plug-in replacement for react-router-redux until it supports
+ * react-router v4.
+ *
+ * @param {Object} location - the next location object on route change.
+ * @return {Object} the action
+ */
 export function updateLocation(location) {
   return { type: LOCATION_CHANGE, payload: { location } };
 }
Updated documentaiton for the routing reducer