Update README.md

README.md

@@ -13,6 +13,8 @@ Differences with HTTP Switchboard:
         - Z is the source hostname axis (aka "scope"), from narrower scopes to global scope
         - X is the request type axis: `*`, `cookie`, `css`, etc.
         - Y is the destination hostname axis (`www.example.com`, `example.com`, `com`, `*`)
+    - Switching scopes in matrix popup does not create/delete scope, it just to allow user to modify rules in a specific scope
+        - Rules in narrower scope(s) still exist and are enforced even if you have the global scope selected
 - Much needed [code refactoring](http://en.wikipedia.org/wiki/Code_refactoring) toward portability/efficiency
     - Big chunks of tired code have been removed, or replaced by small chunks of better code
     - There is no longer a hierarchical data structures for scopes/rules (**major** contribution toward code simplification)