diff --git a/docs/Extending/Adding New Deck Models.md b/docs/Extending/Adding New Deck Models.md
index 3718cff3..6c67f444 100644
--- a/docs/Extending/Adding New Deck Models.md	
+++ b/docs/Extending/Adding New Deck Models.md	
@@ -77,7 +77,7 @@ Depending on the button's action that is triggered, the deck will programmatical
 
 `swipe`: will produce a complex swipe Event, with the position of the start of the swipe, the end of the swipe and some timing information (timestamps of start and end of swipe).
 
-Technically speaking, the deck will start a thread to listen to incoming events. Interaction will be decoded (which key was pressed, when, how, etc.) and presented to Cockpitdecks for handling as a typed Event.
+Technically speaking, the deck will start a thread to listen to incoming events. Interaction will be decoded (which key was pressed, when, how, etc.) and presented to Cockpitdecks as a typed Event.
 
 Depending on the device driver's hardware access, events will either be presented directly to Cockpitdecks, or through a FIFO queue: Driver just enqueues events, Cockpitdecks dequeues events and does the work.
 
diff --git a/docs/Extending/Internals/Deck Internals.md b/docs/Extending/Internals/Deck Internals.md
index 95b522ec..8f27e9f8 100644
--- a/docs/Extending/Internals/Deck Internals.md	
+++ b/docs/Extending/Internals/Deck Internals.md	
@@ -194,12 +194,13 @@ When rendered in a browser window, web deck interaction means are materialised t
 
 #### Attributes
 
-| Attribute | Definition                                                                                                                                                                                                                                                                                                                                                                 |
-| --------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
-| Dimension | The dimension attribute can be a single integer value or a list of two values.<br><br>It determine the size of the button has drawn on the Web deck.<br><br>If the feedback visualisation is an `image`, the `image` attribute specifies the characteristics of the image. `X`is horizontal and correspond to the `width`, `Y` is vertical and correspond to the `height`. |
-| layout    | Layout of the buttons on the web deck canvas.<br>- Offset<br>- Spacing<br>Buttons will be arranged at regular interval, starting from Offset, with supplied spacing between the buttons. Button sizes are specified in the Dimension attribute.                                                                                                                            |
-| hardware  | Configuration information for a specific drawing representation of this hardware button.                                                                                                                                                                                                                                                                                   |
-| options   | Comma-separated list of options, a single option can either be a name=value, or just a name, in which case the value is assumed to be True.<br><br>`options: count=8,active`<br><br>sets options `count`to value 8, and `active` to True. `active` is equivalent to `active=true`.                                                                                         |
+| Attribute    | Definition                                                                                                                                                                                                                                                                                                                                                                 |
+| ------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| Dimension    | The dimension attribute can be a single integer value or a list of two values.<br><br>It determine the size of the button has drawn on the Web deck.<br><br>If the feedback visualisation is an `image`, the `image` attribute specifies the characteristics of the image. `X`is horizontal and correspond to the `width`, `Y` is vertical and correspond to the `height`. |
+| layout       | Layout of the buttons on the web deck canvas.<br>- Offset<br>- Spacing<br>Buttons will be arranged at regular interval, starting from Offset, with supplied spacing between the buttons. Button sizes are specified in the Dimension attribute.                                                                                                                            |
+| hardware     | Configuration information for a specific drawing representation of this hardware button.                                                                                                                                                                                                                                                                                   |
+| empty-button | Minimal Button definition to create an empty, dummy button. This dummy button will becreated and used to generate an "empty" hardware representation (completely `off`). (In other words, if a button with hardware representation is not defined, this definition will be used to create a button.)                                                                       |
+| options      | Comma-separated list of options, a single option can either be a name=value, or just a name, in which case the value is assumed to be True.<br><br>`options: count=8,active`<br><br>sets options `count`to value 8, and `active` to True. `active` is equivalent to `active=true`.                                                                                         |
 
 ### Special Button Representation
 
diff --git a/docs/Extending/Simulator.md b/docs/Extending/Simulator.md
index efc57aa1..f299e2c8 100644
--- a/docs/Extending/Simulator.md
+++ b/docs/Extending/Simulator.md
@@ -10,10 +10,18 @@ In addition to the core simulation software, the Simulator also proposes a few a
 
 The simulation software presents to Cockpitdecks all its reachable « values ». Any value that is accessible in the simulation software is made available to Cockpitdecks through the SimulationData. A sophisticated mechanism updates the data in Cockpitdecks every time the data is modified in the simulator.
 
+For example, Laminar X-Plane extensively uses « *datarefs* », while Microsoft Flight Simulator uses « *simvars* ». They both are values coming from the simulator, and they both can be used in Cockpitdecks.
+
+## Local Values
+
+In addition to simulator data, Cockpitdecks maintains its own set of « local » data, data that is not forwarded to the simulator but that can be used like any other simulator data.
+
 # Instructions
 
 Cockpitdecks offers the Instruction, an action that must be carried out in the simulator software, provided that the simulation software allows for « external action » to be accepted.
 
+Again, as an example, Laminar X-Plane has « *commands* » (offered in two modes of operation), and Microsoft Flight Simulator has « *idontknow* ».
+
 # Simulator Core
 
 The Simulator entity is responsible for maintaining a connection to the Simulator software to collect simulator data values and issue instructions.
diff --git a/docs/Extending/The New View Attribute.md b/docs/Extending/The New View Attribute.md
index a0784ecb..bebdb334 100644
--- a/docs/Extending/The New View Attribute.md	
+++ b/docs/Extending/The New View Attribute.md	
@@ -74,9 +74,18 @@ Command above will be executed 5 seconds after the execution of the activation o
 #### Condition
 
 A `condition` attribute is a formula that is executed before he command. If the result of the formula is evaluated to a non null (non zero) value, the command is executed. Otherwise, the command is not executed.
+
+```yaml
+command: command/to/execute
+condition: ${some/dataref/to/check} 1 -
+```
+
+If the result of the computation of the formula is non zero, the command will be executed.
+
 # Processing
 
 Detection of the new parameter value is easy. Either it is a string representing a command to submit to X-Plane, or it is a list of one or more command blocks. There is no ambiguity.
+
 # Usage
 
 The `view` attribute can be used as a test bed for execution of more than one command in a sequence, a kind of execution of « macro » command, with additional features like conditions and delay of execution.
diff --git a/docs/Extending/Web Decks.md b/docs/Extending/Web Decks.md
index ed9513a6..0d12e9be 100644
--- a/docs/Extending/Web Decks.md	
+++ b/docs/Extending/Web Decks.md	
@@ -2,7 +2,10 @@ In addition to real physical decks, Cockpitdecks offers *Web Decks* rendered in
 
 ![[virtualdecks.jpg]]
 
-This is very handy to design layout for deck a developer does not necessary owns.
+If a Web Deck is detected in an aircraft configuration, Cockpitdecks will automagically start a basic web server to present the Web Deck to the user. The index (home) page of the web server will present all web decks available to the user. Selecting on web deck will start it in another browser window.
+
+Web decks are very handy to design layout for deck a developer does not necessary owns.
+
 Web decks can be (almost) any physical deck represented in Cockpitdecks (most popular brands and models are actually provided with Cockpitdecks), or any next deck model of your fantasy. As an example and proof of concept, Cockpitdecks comes with a fully operational overhead panel for Toliss A321 neo aircraft. Yes, you read it right, you can have Toliss A321 overhead panel on a touch screen or tablet.
 
 # Web Deck Declaration and Use
@@ -30,7 +33,7 @@ deckconfig
 	    ⊢ custom_background_image.png
 ```
 
-Virtual decks are defined like any other deck. Their driver must be `virtualdeck`. They contain a few additional attributes to render them on a HTML web Canvas like background image or color.
+Virtual decks are defined like any other deck. Their driver must be `virtualdeck`. They contain  additional attributes to render them on a HTML web Canvas like background image or color.
 
 ```yaml hl_lines="2"
 name: Virtual Deck 3×2
diff --git a/docs/images/virtual-xtouchmini.png b/docs/images/virtual-xtouchmini.png
new file mode 100644
index 00000000..0ffb9fb1
Binary files /dev/null and b/docs/images/virtual-xtouchmini.png differ