Approach to leading underscores in var names in ES5

es5/README.md

@@ -1178,18 +1178,29 @@
     });
     ```
 
-  - Use a leading underscore `_` when naming private properties.
+  - Never use a leading underscore `_` when naming properties that are meant to
+    be used as private.  This is a form of Hungarian notation (evil!) that
+    unnecessarily pollutes the code.  JavaScript does not really support the
+    concept of variable privacy so there is no need to resort to this kind of
+    tricks to fake it.
 
     ```javascript
     // bad
     this.__firstName__ = 'Panda';
     this.firstName_ = 'Panda';
+    this._firstName = 'Panda';
 
     // good
-    this._firstName = 'Panda';
+    this.firstName = 'Panda';
     ```
 
-  - When saving a reference to `this` use `_this`.
+  - Avoid referencing `this` and opt for scope binding instead.  You typically
+    end up needing it when handling events in jQuery and this technique
+    encourages you to decouple event listeners from their handlers, makes the
+    code simpler and much easier to unit test.
+
+    If you really need to reference the `this` scope, never use `_this` but
+    `context` instead.
 
     ```javascript
     // bad
@@ -1208,13 +1219,19 @@
       };
     }
 
-    // good
+    // bad
     function() {
       var _this = this;
       return function() {
         console.log(_this);
       };
     }
+
+    // good
+    _.bindAll( this, 'handleClickEvent' );
+    function() {
+      $( target ).on( 'click', this.handleClickEvent );
+    }
     ```
 
   - Name your functions. This is helpful for stack traces.