diff --git a/README.md b/README.md
index 9b9b2e5..a9040fd 100644
--- a/README.md
+++ b/README.md
@@ -11,10 +11,14 @@ especially for reading configuration files.
 
 OK, stop talking, show us some code!  
 
-On the left is what you'll normally do, on the right is the ezcf way. Much more elegant isn't it?
+On the left is what you'll normally do, on the right is the ezcf way.  
+**All you need is `import ezcf` first, then `import filename` without extension.** Nothing else!
 
 ![](https://github.com/laike9m/ezcf/raw/master/code_compare.png)
 
+For instance, here we want to load file `config.json`. With a single line of code `import config`,
+everything is done and you're happy.
+
 ## Install
 
     pip install ezcf
@@ -66,6 +70,8 @@ only one of them will be loaded. So it's better not to use multiple documents;
 3. All values in `.ini` files are kept as it is and loaded as a string;
 4. Since XML only allows single root, the whole xml will be loaded as one dict with root's name as variable name;
 5. Namespace package is not supported yet, pull requests are welcome.
+6. Use [**valid variable names**][1], this means key strings in JSON/YAML/INI/XML should be valid Python variable name.
+ Invalid variable name won't do any harm to your program nor will it crash, but you can't use them as expected.
 
 ## Run Tests
 ```
@@ -86,4 +92,7 @@ python setup.py test
 - [x] pypi
 
 ## License
-MIT
\ No newline at end of file
+MIT
+
+
+[1]: https://docs.python.org/3.4/reference/lexical_analysis.html#identifiers
\ No newline at end of file
diff --git a/README.rst b/README.rst
index c03af75..44f0225 100644
--- a/README.rst
+++ b/README.rst
@@ -10,12 +10,16 @@ from these formats, especially for reading configuration files.
 
 OK, stop talking, show us some code!
 
-On the left is what you'll normally do, on the right is the ezcf way.
-Much more elegant isn't it?
+| On the left is what you'll normally do, on the right is the ezcf way.
+| **All you need is ``import ezcf`` first, then ``import filename``
+without extension.** Nothing else!
 
 .. figure:: https://github.com/laike9m/ezcf/raw/master/code_compare.png
    :alt: 
 
+For instance, here we want to load file ``config.json``. With a single
+line of code ``import config``, everything is done and you're happy.
+
 Install
 -------
 
@@ -84,6 +88,11 @@ Something to note before using ezcf:
 4. Since XML only allows single root, the whole xml will be loaded as
    one dict with root's name as variable name;
 5. Namespace package is not supported yet, pull requests are welcome.
+6. Use `**valid variable
+   names** <https://docs.python.org/3.4/reference/lexical_analysis.html#identifiers>`__,
+   this means key strings in JSON/YAML/INI/XML should be valid Python
+   variable name. Invalid variable name won't do any harm to your
+   program nor will it crash, but you can't use them as expected.
 
 Run Tests
 ---------
@@ -109,7 +118,7 @@ Roadmap
 License
 -------
 
-MIT
+MMIT
 
 .. |Build Status| image:: https://travis-ci.org/laike9m/ezcf.svg
    :target: https://travis-ci.org/laike9m/ezcf
diff --git a/ezcf/__init__.py b/ezcf/__init__.py
index 35fb5dd..ebf60c5 100644
--- a/ezcf/__init__.py
+++ b/ezcf/__init__.py
@@ -1,6 +1,6 @@
 __author__ = "laike9m (laike9m@gmail.com)"
 __title__ = 'ezcf'
-__version__ = '0.0.1'
+__version__ = '0.2.0'
 __license__ = 'MIT'
 __copyright__ = 'Copyright 2015 laike9m'