diff --git a/ui/data.js b/ui/data.js
index 8de70c76..98767f1d 100755
--- a/ui/data.js
+++ b/ui/data.js
@@ -71,9 +71,9 @@ var CONFIG = {
 	// NOTE: a "screen" is the number of images that can fit one screen
 	// 		width, as returned by getScreenWidthInImages(..)
 	load_screens: 6,
-	// size of the frame to load relative to LOAD_SCREENS
+	// Size of the frame to load relative to load_screens
 	roll_frame: 1/3,
-	// the threshold size relative to LOAD_SCREENS
+	// The threshold size relative to load_screens
 	load_threshold: 1/4,
 
 	// A threshold after which the image block ratio will be changed form 
@@ -86,8 +86,10 @@ var CONFIG = {
 	// 								image proportions will transition 
 	// 								gradually form square to screen
 	//
+	//
 	// When using array threshold, the gap between top and bottom must 
-	// be at least a couple of zoom_step_scale's.
+	// be at least a couple of zoom_step_scale's to ensure a smooth 
+	// transition over at least several zoom steps.
 	//
 	// NOTE: the array format, threshold order is not important.
 	// NOTE: setting this to an integer may have a side-effect of making
@@ -106,10 +108,14 @@ var CONFIG = {
 		2.5 
 	],
 
+	// The scale applied on each zoom step.
+	//
+	// NOTE: The value should be >1 or zooming will be reversed.
+	zoom_step_scale: 1.2,
+
 	// ribbon scaling limits and defaults...
 	max_screen_images: 12,
 	default_screen_images: 4,
-	zoom_step_scale: 1.2,
 
 	// localStorage prefix...
 	data_attr: 'DATA',
diff --git a/ui/urlhistory.js b/ui/urlhistory.js
index a29238f8..dad2290c 100755
--- a/ui/urlhistory.js
+++ b/ui/urlhistory.js
@@ -79,7 +79,7 @@ function setupBaseURLHistory(){
 // Push a url to top of history...
 //
 // NOTE: this does not care if a url exists or not, all other instances 
-// 		will get removed...
+// 		of the same will get removed...
 // NOTE: this will not do any loading...
 // NOTE: this will save history state to localStorage...
 function pushURLHistory(url){
@@ -107,6 +107,7 @@ function getURLHistoryPosition(){
 
 // Get next/prev relative position in history...
 //
+// NOTE: these will skip non-existing urls...
 function getURLHistoryNext(){
 	var non_existing = getNonExistingBaseURLs()
 	var i = getURLHistoryPosition() + 1