docs improved

docs/guide/i18n.md

@@ -356,7 +356,8 @@ class Module extends \yii\base\Module
 }
 ```
 
-In the example above we are using wildcard for matching and then filtering each category per needed file.
+In the example above we are using wildcard for matching and then filtering each category per needed file. Instead of using `fileMap` you can simply
+use convention of category mapping to the same named file and use `Module::t('validation')` or `Module::t('form)` directly.
 
 ###Translating widgets messages
 
@@ -405,6 +406,8 @@ class Menu extends Widget
 }
 ```
 
+Instead of using `fileMap` you can simply use convention of category mapping to the same named file and use `Menu::t('messages')` directly.
+
 > **Note**: For widgets you also can use i18n views, same rules as for controllers are applied to them too.
 
 TBD: provided classes overview.