diff --git a/README.md b/README.md
index 136ec05..c016951 100644
--- a/README.md
+++ b/README.md
@@ -38,4 +38,96 @@ to the "require" section of your composer.json.
Usage
-----
-This extension allows integration with PSR-6 compatible cache for Yii1.
+This extension allows integration with [PSR-6](https://www.php-fig.org/psr/psr-6/) compatible cache for Yii1.
+It provides several instruments for that. Please choose the one suitable for your particular needs.
+
+
+### Wrap PSR cache pool into Yii cache
+
+The most common use case for PSR caceh involvement into Yii application is usage of 3rd party cache library.
+This can be achieved using `\yii1tech\psr\cache\Cache` as Yii cache component.
+
+Application configuration example:
+
+```php
+ [
+ 'cache' => [
+ 'class' => \yii1tech\psr\cache\Cache::class,
+ 'psrCachePool' => function () {
+ // ...
+ return new ExamplePsrCachePool(); // instantiate 3rd party cache library
+ },
+ ],
+ // ...
+ ],
+ // ...
+];
+```
+
+
+### Wrap Yii cache into PSR cache pool
+
+There is another use case related to PSR cache besides bootstrapping eternal cache storage.
+Sometimes 3rd party libraries may require PSR cache pool instance to be passed to them in order to function.
+`\Psr\Cache\CacheItemPoolInterface` allows wrapping standard Yii cache component into a PSR compatible cache pool.
+
+Application configuration example:
+
+```php
+ [
+ 'cache' => [
+ 'class' => \CMemCache::class,
+ 'servers' => [
+ // ...
+ ],
+ ],
+ \Psr\Cache\CacheItemPoolInterface::class => [
+ 'class' => \yii1tech\psr\cache\CacheItemPool::class,
+ 'cache' => 'cache',
+ ],
+ // ...
+ ],
+ // ...
+];
+```
+
+Usage example:
+
+```php
+getComponent(CacheItemPoolInterface::class);
+
+ $item = $pool->getItem('categories-count');
+ if ($item->isHit()) {
+ return $item->get();
+ }
+
+ $value = Category::model()->count();
+
+ $item->set($value)
+ ->expiresAfter(DateInterval::createFromDateString('1 hour'));
+
+ $pool->save($item);
+
+ return $value;
+}
+```
+
+
+### Simplified interface
+
+
+### Using cache tags
+
diff --git a/src/CacheItemPool.php b/src/CacheItemPool.php
index d98e72d..9c62a74 100644
--- a/src/CacheItemPool.php
+++ b/src/CacheItemPool.php
@@ -8,6 +8,29 @@
use Yii;
/**
+ * CacheItemPool allows wrapping standard Yii cache component into a PSR compatible cache pool.
+ *
+ * Application configuration example:
+ *
+ * ```php
+ * return [
+ * 'components' => [
+ * 'cache' => [
+ * 'class' => \CMemCache::class,
+ * 'servers' => [
+ * // ...
+ * ],
+ * ],
+ * \Psr\Cache\CacheItemPoolInterface::class => [
+ * 'class' => \yii1tech\psr\cache\CacheItemPool::class,
+ * 'cache' => 'cache',
+ * ],
+ * // ...
+ * ],
+ * // ...
+ * ];
+ * ```
+ *
* @author Paul Klimov
* @since 1.0
*/