[BridgeAbstract] Add 'Queried Context' section

BridgeAbstract.md

@@ -193,6 +193,39 @@ This function returns the URI to the destination site of the bridge. It will be
 	}
 ```
 
+## Queried context
+
+The queried context is defined via `PARAMETERS` and can be accessed via `$this->queriedContext`.
+It provides a way to identify which context the bridge is called with.
+
+Example:
+
+```PHP
+...
+	const PARAMETERS = array(
+		'By user name' => array(
+			'u' => array('name' => 'Username')
+		),
+		'By user ID' => array(
+			'id' => array('name' => 'User ID')
+		)
+	);
+
+...
+```
+
+In this example `$this->queriedContext` will either return **By user name** or **By user ID**. The queried context might return no value, so the best way to handle it is by using a case-structure:
+
+```PHP
+switch($this->queriedContext){
+	case 'By user name':
+		break;
+	case 'By user ID':
+		break;
+	default: // Return default value
+}
+```
+
 # Helper functions
 
 Helper functions are independent function that help you to manage specific events in your bridges.