Updated code style recommendataions - PHPDoc blocks

docs/internals/core-code-style.md

@@ -147,17 +147,23 @@ class Foo
  - `@param`, `@var`, `@property` and `@return` must declare types as `boolean`, `integer`, `string`, `array` or `null`. 
    You can use a class names as well such as `Model` or `ActiveRecord`. 
  - For a typed arrays use `ClassName[]`.
- - `@return` should explicitly describe what exactly will be returned
+ - The first line of the PHPDoc must describe the purpose of the method.
+ - If method checks something (`isActive`, `hasClass`, etc) the first line should start with `Checks whether`.
+ - `@return` should explicitly describe what exactly will be returned.
   
 ```php
 /**
- * Returns a boolean whether the IP is in subnet range
+ * Checkes whether the IP is in subnet range
  * 
  * @param string $ip an IPv4 or IPv6 address
  * @param integer $cidr the CIDR lendth
  * @param string $range subnet in CIDR format e.g. `10.0.0.0/8` or `2001:af::/64`
  * @return boolean whether the IP is in subnet range
  */
+ private function inRange($ip, $cidr, $range) 
+ {
+   // ...
+ }
 ```
 
 ### 4.5 Constructors