Simulator warnings, etc.

docs/reference/radio/on-data-received.md

@@ -7,6 +7,10 @@ Run part of a program when the micro:bit receives a
 
 * the part of the program to run when the micro:bit receives information over ``radio``.
 
+### Simulator
+
+This function only works on the micro:bit, not in browsers.
+
 ### Example
 
 This program keeps sending numbers that says how fast the micro:bit is

docs/reference/radio/receive-number.md

@@ -2,10 +2,14 @@
 
 Receives the next number sent by a micro:bit in the same ``radio`` group.
 
-### Return value
+### Returns
 
 * the first  [number](/reference/types/number) that the micro:bit received. If it did not receive any numbers, this function will return `0`.
 
+### Simulator
+
+This function only works on the micro:bit, not in browsers.
+
 ### Example: Simple number receiver
 
 This example receives the number broadcasted another micro:bit and shows it

docs/reference/radio/receive-string.md

@@ -6,10 +6,14 @@ Find the next string sent by `radio` from another micro:bit.
 radio.receiveString()
 ```
 
-### Return value
+### Returns
 
 * the first [string](/reference/types/string) that was sent. If no string was sent, then this function returns an empty (blank) string.
 
+### Simulator
+
+This function only works on the micro:bit, not in browsers.
+
 ### Example: Simple receiver
 
 Show the string sent by another micro:bit.

docs/reference/radio/received-signal-strength.md

@@ -13,7 +13,7 @@ it needs to run **receive number** first.
 * a [number](/reference/types/number) between `255` and `0` that means
 how strong the signal is.
 
-## Simulator
+### Simulator
 
 This function only works on the micro:bit, not in browsers.
 

docs/reference/radio/send-number.md

@@ -6,6 +6,10 @@ Broadcast a number to other micro:bits connected via ``radio``.
 
 * num - a number to send.
 
+### Simulator
+
+This function only works on the micro:bit, not in browsers.
+
 ### Example: Broadcasting acceleration
 
 This example broadcasts the value of your micro:bit's ``acceleration`` in the `x` direction 

docs/reference/radio/send-string.md

@@ -1,7 +1,5 @@
 # Send String
 
-
-
 Sends a string to other micro:bits in the area connected by radio.
 
 ```sig
@@ -12,6 +10,12 @@ radio.sendString("Hello!")
 
 * `text` is a [String](/reference/types/string) to send by radio.
 
+### Simulator
+
+This function only works on the micro:bit, not in browsers.
+
+
+
 ### Example: Two-way radio
 
 If you load this program onto two or more micro:bits, you can send a code word from one of them to the others by pressing button `A`.

docs/reference/radio/set-group.md

@@ -14,6 +14,10 @@ to talk to each other because they will have the same group ID.
 
 * ``id`` is a [number](/reference/types/number) from ``0`` to ``255``.
 
+### Simulator
+
+This function only works on the micro:bit, not in browsers.
+
 ### Example
 
 This program makes the group ID equal 128.

docs/reference/radio/set-transmit-power.md

@@ -8,7 +8,7 @@ The scientific name for the strength of the ``radio`` signal is
 can be measured as -30 dBm, and a strength of `7` can be
 measured as +4 dBm.
 
-## Range
+### Range
    
 If your micro:bit is sending with a strength of `7`, and you are in
 an open area without many other computers around, the micro:bit signal
@@ -19,6 +19,10 @@ can reach as far as 70 meters (about 230 feet).
 * a [number](/reference/types/number) between ``0`` and ``7`` that
 means how strong the signal is.
 
+### Simulator
+
+This function only works on the micro:bit, not in browsers.
+
 ### Example
 
 This program makes the ``radio`` send at full strength.

docs/reference/radio/write-value-to-serial.md

@@ -9,21 +9,11 @@ The format for received data printed to serial is as follows
 - [send value](/reference/radio/send-number) - ```{v:Value,t:MicrobitTimeAlive,s:Unused,n:"Name"}```
 - [send string](/reference/radio/send-string) - ```{}``` (currently unavailable)
 
-## Important Security Consideration
 
-The functions in the ``radio`` namespace allow the BBC micro:bit to communicate with other micro:bits.
 
-This API does not contain any form of encryption, authentication or authorization. It's purpose is solely for use as a teaching aid to demonstrate how simple communications operates, and to provide a sandpit through which learning can take place.
+### Simulator
 
-For serious applications, BLE should be considered a substantially more secure alternative.
-
-```sig
-radio.writeValueToSerial()
-```
-
-### Parameters
-
-* None
+This function only works on the micro:bit, not in browsers.
 
 ### Examples