diff --git a/README.md b/README.md
index 9ff8e95..7d5a49b 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,19 @@ NodeJS validation middleware for express router using schemas for both body and
 
 This library allows you to use any validation library, even your own. Examples are using [validator](https://github.com/validatorjs/validator.js)
 
-# Installation and usage
+# Table of contents
+1. [Installation](#installation)
+2. [Quick example](#quick-example)
+3. [Schema structure](#schema-structure)
+4. [Optional fields](#optional-fields)
+5. [Validating both body and parameters](#validating-both-body-and-parameters)
+6. [Validation output](#validation-output)
+7. [Using field values in messages](#using-field-values-in-messages)
+8. [Async/await validation](#asyncawait-validation)
+9. [Cross field validation](#cross-field-validation)
+10. [Contributing](#contributing)
+
+## Installation
 > npm i nodejs-schema-validator
 
 ## Quick example
@@ -40,6 +52,7 @@ router.post(
 );
 ```
 
+## Schema structure
 Here's a breakdown of how the schema is structured:
 
 ```js
@@ -69,6 +82,22 @@ const schemaExample = {
     }
 }
 ```
+
+## Optional fields
+Marking fields as optional will validate only when they are not empty.
+```js
+const schema = {
+    vatNo: {
+        // Some fields can be optional
+        optional: true,
+        rules: [
+            rule: (input) => !validator.isValidVatNo(input),
+            message: 'Please insert a valid VAT number of leave empty'
+        ]
+    }
+}
+```
+
 ## Validating both body and parameters
 Example of how to validate both body and url parameters
 
@@ -104,7 +133,7 @@ router.put(
 )
 ```
 
-
+## Validation output
 Validation failure returns status code 422 with a body in this format:
 ```js
 {
@@ -117,7 +146,6 @@ Validation failure returns status code 422 with a body in this format:
 }
 ```
 
-## Custom validation output
 In case you want to customize the output and status code of the failure you can pass a function as the second parameter to the middleware. It can be passed to both `paramSchemaValidator` and `bodySchemaValidator`.
 
 ```js
@@ -133,6 +161,7 @@ router.post(
 ```
 
 ## Using field values in messages
+Field names wrapped in double curly braces will be replaced with their values. **Please note that there should be no space between the field name and the braces**.
 ```js
 const schema = {
     amount: {
@@ -146,7 +175,7 @@ const schema = {
 };
 ```
 
-## Validating with async/await
+## Async/await validation
 Schema rules support async methods. Here's an example:
 
 ```js
@@ -154,7 +183,7 @@ const schema = {
     email: {
         rules: [
             {
-                rule: async (input) => await emailExists(),
+                rule: async (input) => await emailExists(input),
                 message: 'Email address {{email}} already exists'
             }
         ]
diff --git a/package.json b/package.json
index 777a2ba..c4c04c8 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "nodejs-schema-validator",
-  "version": "0.10.2",
+  "version": "0.10.3",
   "description": "NodeJS validation using schemas",
   "main": "./src/schema-validator.js",
   "scripts": {