diff --git a/js/main.js b/js/main.js
index c0c63006..a8572c6a 100644
--- a/js/main.js
+++ b/js/main.js
@@ -174,7 +174,17 @@ var MM = (function() {
 	 * argument speed Number - The speed of the hide animation.
 	 * argument callback function - Called when the animation is done.
 	 */
-	var hideModule = function(module, speed, callback) {
+	var hideModule = function(module, speed, callback, options) {
+		options = options || {};
+
+		// set lockString if set in options.
+		if (options.lockString) {
+			Log.log("Has lockstring: " + options.lockString);
+			if (module.lockStrings.indexOf(options.lockString) === -1) {
+				module.lockStrings.push(options.lockString);
+			}
+		}
+
 		var moduleWrapper = document.getElementById(module.identifier);
 		if (moduleWrapper !== null) {
 			moduleWrapper.style.transition = "opacity " + speed / 1000 + "s";
@@ -183,7 +193,7 @@ var MM = (function() {
 			clearTimeout(module.showHideTimer);
 			module.showHideTimer = setTimeout(function() {
 				// To not take up any space, we just make the position absolute.
-				// since it"s fade out anyway, we can see it lay above or
+				// since it's fade out anyway, we can see it lay above or
 				// below other modules. This works way better than adjusting
 				// the .display property.
 				moduleWrapper.style.position = "absolute";
@@ -200,7 +210,30 @@ var MM = (function() {
 	 * argument speed Number - The speed of the show animation.
 	 * argument callback function - Called when the animation is done.
 	 */
-	var showModule = function(module, speed, callback) {
+	var showModule = function(module, speed, callback, options) {
+		options = options || {};
+
+		// remove lockString if set in options.
+		if (options.lockString) {
+			var index = module.lockStrings.indexOf(options.lockString)
+			if ( index !== -1) {
+				module.lockStrings.splice(index, 1);
+			}
+		}
+
+		// Check if there are no more lockstrings set, or the force option is set.
+		// Otherwise cancel show action.
+		if (module.lockStrings.length !== 0 && options.force !== true) {
+			Log.log("Will not show " + module.name + ". LockStrings active: " + module.lockStrings.join(","));
+			return;
+		}
+
+		// If forced show, clean current lockstrings.
+		if (module.lockStrings.length !== 0 && options.force === true) {
+			Log.log("Force show of module: " + module.name);
+			module.lockStrings = [];
+		}
+
 		var moduleWrapper = document.getElementById(module.identifier);
 		if (moduleWrapper !== null) {
 			moduleWrapper.style.transition = "opacity " + speed / 1000 + "s";
@@ -419,10 +452,11 @@ var MM = (function() {
 		 * argument module Module - The module hide.
 		 * argument speed Number - The speed of the hide animation.
 		 * argument callback function - Called when the animation is done.
+		 * argument options object - Optional settings for the hide method.
 		 */
-		hideModule: function(module, speed, callback) {
+		hideModule: function(module, speed, callback, options) {
 			module.hidden = true;
-			hideModule(module, speed, callback);
+			hideModule(module, speed, callback, options);
 		},
 
 		/* showModule(module, speed, callback)
@@ -431,10 +465,11 @@ var MM = (function() {
 		 * argument module Module - The module show.
 		 * argument speed Number - The speed of the show animation.
 		 * argument callback function - Called when the animation is done.
+		 * argument options object - Optional settings for the hide method.
 		 */
-		showModule: function(module, speed, callback) {
+		showModule: function(module, speed, callback, options) {
 			module.hidden = false;
-			showModule(module, speed, callback);
+			showModule(module, speed, callback, options);
 		}
 	};
 
diff --git a/js/module.js b/js/module.js
index 9c26bc7b..fe669cee 100644
--- a/js/module.js
+++ b/js/module.js
@@ -20,6 +20,10 @@ var Module = Class.extend({
 	// Timer reference used for showHide animation callbacks.
 	showHideTimer: null,
 
+	// Array to store lockStrings. These stings are used to lock 
+	// visibility when hiding and showing module.
+	lockStrings: [],
+
 	/* init()
 	 * Is called when the module is instantiated.
 	 */
@@ -314,15 +318,24 @@ var Module = Class.extend({
 	 *
 	 * argument speed Number - The speed of the hide animation.
 	 * argument callback function - Called when the animation is done.
+	 * argument options object - Optional settings for the hide method.
 	 */
-	hide: function(speed, callback) {
+	hide: function(speed, callback, options) {
+		if (typeof callback === "object") {
+			options = callback;
+			callback = function() {};
+		}
+
 		callback = callback || function() {};
+		options = options || {};
 
 		var self = this;
 		MM.hideModule(self, speed, function() {
 			self.suspend();
 			callback();
-		});
+		}, options);
+
+		Log.log(options);
 	},
 
 	/* showModule(module, speed, callback)
@@ -330,10 +343,19 @@ var Module = Class.extend({
 	 *
 	 * argument speed Number - The speed of the show animation.
 	 * argument callback function - Called when the animation is done.
+	 * argument options object - Optional settings for the hide method.
 	 */
-	show: function(speed, callback) {
+	show: function(speed, callback, options) {
+		if (typeof callback === "object") {
+			options = callback;
+			callback = function() {};
+		}
+
+		callback = callback || function() {};
+		options = options || {};
+
 		this.resume();
-		MM.showModule(this, speed, callback);
+		MM.showModule(this, speed, callback, options);
 	}
 });
 
@@ -347,7 +369,7 @@ Module.create = function(name) {
 			return obj;
 		}
 
-		var temp = obj.constructor(); // give temp the original obj"s constructor
+		var temp = obj.constructor(); // give temp the original obj's constructor
 		for (var key in obj) {
 			temp[key] = cloneObject(obj[key]);
 		}
diff --git a/modules/README.md b/modules/README.md
index e7a23abd..d157c983 100644
--- a/modules/README.md
+++ b/modules/README.md
@@ -283,26 +283,93 @@ If you want to send a notification to the node_helper, use the `sendSocketNotifi
 this.sendSocketNotification('SET_CONFIG', this.config);
 ````
 
-####`this.hide(speed, callback)`
-***speed* Number** - Optional, The speed of the hide animation in milliseconds.
+####`this.hide(speed, callback, options)`
+***speed* Number** - Optional (Required when setting callback or options), The speed of the hide animation in milliseconds.
 ***callback* Function** - Optional, The callback after the hide animation is finished.
+***options* Function** - Optional, Object with additional options for the hide action (see below).
 
 To hide a module, you can call the `hide(speed, callback)` method. You can call the hide method on the module instance itself using `this.hide()`, but of course you can also hide another module using `anOtherModule.hide()`.
 
+Possible configurable options:
+
+- `lockString` - String - When setting lock string, the module can not be shown without passing the correct lockstring. This way (multiple) modules can prevent a module from showing. It's considered best practice to use your modules identifier as the locksString: `this.identifier`. See *visibility locking* below.
+
+
 **Note 1:** If the hide animation is canceled, for instance because the show method is called before the hide animation was finished, the callback will not be called.<br>
 **Note 2:** If the hide animation is hijacked (an other method calls hide on the same module), the callback will not be called.<br>
 **Note 3:** If the dom is not yet created, the hide method won't work. Wait for the `DOM_OBJECTS_CREATED` [notification](#notificationreceivednotification-payload-sender).
 
-####`this.show(speed, callback)`
-***speed* Number** - Optional, The speed of the show animation in milliseconds.
+
+####`this.show(speed, callback, options)`
+***speed* Number** - Optional (Required when setting callback or options), The speed of the show animation in milliseconds.
 ***callback* Function** - Optional, The callback after the show animation is finished.
+***options* Function** - Optional, Object with additional options for the show action (see below).
 
 To show a module, you can call the `show(speed, callback)` method. You can call the show method on the module instance itself using `this.show()`, but of course you can also show another module using `anOtherModule.show()`.
 
+Possible configurable options:
+
+- `lockString` - String - When setting lock string, the module can not be shown without passing the correct lockstring. This way (multiple) modules can prevent a module from showing. See *visibility locking- below.
+- `force` - Boolean - When setting the force tag to `true`, the locking mechanism will be overwritten. Use this option with caution. It's considered best practice to let the usage of the force option be use- configurable. See *visibility locking* below.
+
 **Note 1:** If the show animation is canceled, for instance because the hide method is called before the show animation was finished, the callback will not be called.<br>
 **Note 2:** If the show animation is hijacked (an other method calls show on the same module), the callback will not be called.<br>
 **Note 3:** If the dom is not yet created, the show method won't work. Wait for the `DOM_OBJECTS_CREATED` [notification](#notificationreceivednotification-payload-sender).
 
+####Visibility locking
+Visiblity locking helps the module system to prevent unwanted hide/show actions. The following scenario explains the concept:
+
+**Module B asks module A to hide:**
+````
+moduleA.hide(0, {lockString: "module_b_identifier"});
+````
+Module A is now hidden, and has an lock array with the following strings: 
+````
+moduleA.lockStrings == ["module_b_identifier"]
+moduleA.hidden == true
+````
+**Module C asks module A to hide:**
+````
+moduleA.hide(0, {lockString: "module_c_identifier"});
+````
+Module A is now hidden, and has an lock array with the following strings:
+````
+moduleA.lockStrings == ["module_b_identifier", "module_c_identifier"]
+moduleA.hidden == true
+````
+**Module B asks module A to show:**
+````
+moduleA.show(0, {lockString: "module_b_identifier"});
+````
+The lockString will be removed from moduleA’s locks array, but since there still is an other lock string available, the module remains hidden:
+````
+moduleA.lockStrings == ["module_c_identifier"]
+moduleA.hidden == true
+````
+**Module C asks module A to show:**
+````
+moduleA.show(0, {lockString: "module_c_identifier"});
+````
+The lockString will be removed from moduleA’s locks array, and since this will result in an empty lock array, the module will be visible:
+````
+moduleA.lockStrings == []
+moduleA.hidden == false
+````
+
+**Note:** The locking mechanism can be overwritten by using the force tag:
+````
+moduleA.show(0, {force: true});
+````
+This will reset the lockstring array, and will show the module.
+````
+moduleA.lockStrings == []
+moduleA.hidden == false
+````
+
+Use this `force` method with caution. See `show()` method for more information.
+
+
+
 ####`this.translate(identifier)`
 ***identifier* String** - Identifier of the string that should be translated.