diff --git a/.release.json b/.release.json
new file mode 100644
index 0000000..7d6cca7
--- /dev/null
+++ b/.release.json
@@ -0,0 +1,9 @@
+{
+  "source": {
+    "repo_url": "https://github.com/onfido/onfido-openapi-spec",
+    "short_sha": "c4128df",
+    "long_sha": "c4128df7b4043986aa33fa70f1fd6d620a314f78",
+    "version": ""
+  },
+  "release": "v4.0.0"
+}
diff --git a/README.md b/README.md
index 0a59335..c71c193 100644
--- a/README.md
+++ b/README.md
@@ -15,7 +15,7 @@ This version uses Onfido API v3.6. Refer to our [API versioning guide](https://d
 Building the API client library requires:
 
 1. Java 1.8+
-2. Maven/Gradle
+3. Maven/Gradle
 
 ### Installation
 
@@ -150,13 +150,19 @@ try {
 }
 ```
 
-### Recommendation
+### Recommendations
 
-It's recommended to create an instance of `ApiClient` per thread in a multithreaded environment to avoid any potential issues.
+### Don't share DefaultApi among different threads
+
+It's recommended to create an instance of `DefaultApi` per thread in a multithreaded environment to avoid any potential issues.
+
+#### Do not use additional properties
+
+Retain from using `getAdditionalProperty()` or `getAdditionalProperties()` methods to access not defined properties to avoid breaking changes when these fields will appear.
 
 ## Contributing
 
-This library is automatically generated using [OpenAPI Generator](https://openapi-generator.tech) - version: 7.6.0; therefore all the contributions, except tests files, should target [Onfido OpenAPI specification repository](https://github.com/onfido/onfido-openapi-spec/tree/master) instead of this repository.
+This library is automatically generated using [OpenAPI Generator](https://openapi-generator.tech) (version: 7.6.0); therefore all the contributions, except tests files, should target [Onfido OpenAPI specification repository](https://github.com/onfido/onfido-openapi-spec/tree/master) instead of this repository.
 
 For contributions to the tests instead, please follow the steps below:
 
@@ -167,11 +173,28 @@ For contributions to the tests instead, please follow the steps below:
 5. Push to the branch (`git push origin my-new-feature`)
 6. Create a new Pull Request
 
+## Versioning policy
+
+[Semantic Versioning](https://semver.org) policy is used for library versioning, following guidelines and limitations below:
+
+- MAJOR versions (x.0.0) might:
+  - target a new API version
+  - include non-backward compatible change
+- MINOR versions (0.x.0) might:
+  - add a new functionality, non-mandatory parameter or property
+  - deprecate an old functionality
+  - include non-backward compatible change to a functionality which is:
+    - labelled as alpha or beta
+    - completely broken and not usable
+- PATCH version (0.0.x) might:
+  - fix a bug
+  - include backward compatible changes only
+
 ## More documentation
 
 More documentation and code examples can be found at <https://documentation.onfido.com>.
 
 ## Support
 
-Should you encounter any technical issues during integration, please contact Onfido's Customer Support team
-via the [Customer Experience Portal](https://public.support.onfido.com/) which also includes support documentation.
+Should you encounter any technical issues during integration, please contact Onfido's Customer Support team via the [Customer Experience Portal](https://public.support.onfido.com/) which also includes support documentation.
+