Add documentation for vatSys and Euroscope sector extension

docs/controller-skills/Client-Guides/euroscope-setup.md

@@ -76,4 +76,41 @@ Just select one of the four ATIS dialogs and set it up as you usually would, the
 
 ``` { .yaml .copy }
 https://vatatis.nz/gen?arr=$arrrwy($atisairport)&dep=$deprwy($atisairport)&info=$atiscode&metar=$metar($atisairport)
-```
+```
+
+## Sector Extensions for VATSIM Radar
+
+EuroScope does **not** support automatic sector extensions.  
+Controllers must manually enter their extension lines in the **Controller Info** field.
+
+Use the standard New Zealand sector–frequency mapping:
+
+| Sector | Frequency |
+|--------|-----------|
+| **OCR** | 123.9 |
+| **BAY** | 119.5 |
+| **NAK** | 123.7 |
+| **OHA** | 126.2 |
+| **STH** | 129.3 |
+| **KAI** | 129.4 |
+
+#### Example Manual Entry
+If you are controlling **OCR** and extending the country, your Controller Info should include:
+
+`Extending BAY 119.5, NAK 123.7, OHA 126.2, KAI 129.4, STH 129.3`
+
+![Controller Infomation](../assets/es_controller_info_extending.png)
+
+---
+
+### Manual Updates Required in EuroScope
+
+EuroScope does **not** automatically update your Controller Info when:
+
+- When your primed frequencies are changed
+
+Because of this limitation:
+
+> **Controllers are expected to manually update their Controller Info whenever sector coverage changes.**
+
+This ensures VATSIM Radar has up‑to‑date extension information.

docs/controller-skills/Client-Guides/vatSys-setup.md

@@ -70,4 +70,23 @@ To check what plugins are currently installed with your client, go to `Info > Ab
   <figcaption>vatSys Info Menu</figcaption>
 </figure>
 
+## Sector Extensions for VATSIM Radar
 
+The New Zealand vatSys profile includes the **VATNZ Plugin** by default.  
+This plugin automatically updates your extension lines based on which frequencies you have **primed** or **de‑primed**.
+
+Because of this, vatSys controllers **do not** need to manually enter extension information.  
+Your Controller Info will update automatically as you change your primed frequencies.
+
+#### How it works
+- When you **prime** a frequency, the plugin adds the correct sector extension lines.  
+- When you **de‑prime** a frequency, the plugin removes the corresponding extension lines.  
+
+This ensures that VATSIM Radar always see accurate, real‑time sector coverage for New Zealand.
+
+#### Manual action is not required
+Unlike EuroScope, vatSys has full capability to:
+- detect your active frequency  
+- update your Controller Info automatically  
+
+As long as you are using the latest **New Zealand Profile**, the plugin will handle all extension logic for you.