diff --git a/README.md b/README.md
index d0f5900..9c6edd5 100644
--- a/README.md
+++ b/README.md
@@ -6,21 +6,21 @@ This repository contains Adyen API definition files, represented in the [OpenAPI
 
 ## Folder structure
 
-API definitions in this repository are organized into two subfolders:
+API definitions in this repository are organized into two sub-folders:
 
 ```
    /json – Definition files in the json format.
    /yaml – Definition files in the yaml format.
 ```
 
-We support the OpenAPI version 3.0.0.
+We support the OpenAPI version 3.0.3.
 
 ## Usage
   
 There are multiple ways you can use the OpenAPI definition to explore the Adyen API:
 -	If you want to see the API definitions in action, visit the [Adyen API Explorer](https://docs.adyen.com/api-explorer/) portal.
 -	If you prefer to use the classic Swagger toolset, upload these definitions to the [Swagger Editor](http://editor.swagger.io/) or [SwaggerHub](https://swaggerhub.com/).
--	Also we recommend you use [Postman](https://www.getpostman.com/postman) to import the API definition and create your personal collection of requests.
+-	Also, we recommend you use [Postman](https://www.getpostman.com/postman) to import the API definition and create your personal collection of requests.
 
 ## Vendor extensions
 
@@ -32,7 +32,7 @@ This extension provides a list of all endpoint groups for the selected API.
 
 For example:
 
-```
+``` yaml
 x-groups:
   - General
   - Modifications
@@ -44,7 +44,7 @@ These extensions specify how to group endpoints and sort them within a group.
 
 For example:
 
-```
+``` yaml
 paths:
     ...
     post:
@@ -53,10 +53,39 @@ paths:
       x-sortIndex: 5
    ...
 ```
-  
+
+### x-publicVersion
+
+This is an auxiliary extension that help us verify that the current API version is publicly available.
+
+### x-addedInVersion, x-deprecatedInVersion and x-deprecatedMessage
+
+These extensions help us add information when a certain endpoint or field has been added, and later when they are deprecated. 
+
+In addition, the `x-deprecatedMessage` can contain a human-readable message explaining what to use instead of a deprecated API, which provides much better developer experience:
+
+``` yaml
+        recurringDetailReference:
+          deprecated: true
+          x-deprecatedInVersion: 49
+          x-deprecatedMessage: Use `storedPaymentMethodId` instead.
+          description: This is the `recurringDetailReference` returned in the response when you created the token.
+          type: string
+        storedPaymentMethodId:
+          x-addedInVersion: 49
+          description: This is the `recurringDetailReference` returned in the response when you created the token.
+          type: string
+```
+
+### x-oneOf, x-anyOf, x-not and x-allOf
+
+These extensions are equivalent to those from the [JSON Schema](https://json-schema.org/understanding-json-schema/reference/combining.html) but don't enforce strict validation.
+
+We use them in some rare cases when we need to avoid validation issues with open-source tooling, while still being able to display this information in our [API Explorer](https://docs.adyen.com/api-explorer/).
+
 ## Support
   
-If you have a feature request, or spotted a bug or a technical problem, create a GitHub issue. For other questions, contact our [support team](https://support.adyen.com/hc/en-us/requests/new?ticket_form_id=360000705420).
+If you have a feature request, or spotted a bug or a technical problem, create a GitHub issue. For other questions, contact our [Team](https://www.adyen.help/hc/en-us/community/topics).
   
 ## License