README.md in preserve-rds-snapshot-0.2.0 vs README.md in preserve-rds-snapshot-0.3.0

@@ -1,9 +1,22 @@
 # preserve-rds-snapshot
 
 Amazon RDS create a snapshot automatically. Snapshot that is created automatically, will be lost when the instance is terminated. This script preserve db snapshots by copy snapshots.
 
+### AWS API requirement
+
+* RDS
+  * describe_db_instances
+  * describe_db_snapshots
+  * copy_db_snapshot
+  * delete_db_snapshots
+  * list_tags_for_resources
+* EC2
+  * describe_security_groups
+
+NOTE: describe_security_groups is required to get the AWS Account Number. You can use the '--aws-account-number' option instead.
+
 ## Installation
 
 Add this line to your application's Gemfile:
 
 ```ruby
@@ -42,9 +55,10 @@
   s, [--secret-access-key=SECRET_ACCESS_KEY]               # AWS secret access key.
   r, [--region=REGION]                                     # AWS region.
       [--shared-credentials-path=SHARED_CREDENTIALS_PATH]  # AWS shared credentials path.
   i, [--instance=INSTANCE]                                 # target DB Instance
  ```
+
 
 ## Development
 
 After checking out the repo, run `bin/setup` to install dependencies. Then, run `bin/console` for an interactive prompt that will allow you to experiment. Run `bundle exec preserve-rds-snapshot` to use the code located in this directory, ignoring other installed copies of this gem.