diff --git a/versions/3.0.md b/versions/3.0.md
index a0c0ee772e..b661c6b579 100644
--- a/versions/3.0.md
+++ b/versions/3.0.md
@@ -453,6 +453,7 @@ Field Name | Type | Description
parameters | [[Parameter Object](#parameterObject) | [Reference Object](#referenceObject)] | A list of parameters that are applicable for this operation. If a parameter is already defined at the [Path Item](#pathItemParameters), the new definition will override it, but can never remove it. The list MUST NOT include duplicated parameters. A unique parameter is defined by a combination of a [name](#parameterName) and [location](#parameterIn). The list can use the [Reference Object](#referenceObject) to link to parameters that are defined at the [OpenAPI Object's parameters](#oasParameters).
requestBody | [[Request Body Object](#requestBodyObject) | [Reference Object](#referenceObject)] | The request body applicable for this operation.
responses | [Responses Object](#responsesObject) | **Required.** The list of possible responses as they are returned from executing this operation.
+callback responses | [Callback Responses Object](#callbackObject) | The list of possible callback responses as they are returned from executing this operation.
schemes | [`string`] | The transfer protocol for the operation. Values MUST be from the list: `"http"`, `"https"`, `"ws"`, `"wss"`. The value overrides the OpenAPI Object [`schemes`](#oasSchemes) definition.
deprecated | `boolean` | Declares this operation to be deprecated. Usage of the declared operation should be refrained. Default value is `false`.
security | [[Security Requirement Object](#securityRequirementObject)] | A declaration of which security schemes are applied for this operation. The list of values describes alternative security schemes that can be used (that is, there is a logical OR between the security requirements). This definition overrides any declared top-level [`security`](#oasSecurity). To remove a top-level security declaration, an empty array can be used.
@@ -1050,6 +1051,36 @@ Response with no return value:
description: object created
```
+#### Callback Object
+
+A container for possible out-of band callbacks from an operation. A callback may be returned from an operation, calling back to the path specified in the operation object.
+
+##### Patterned Fields
+Field Pattern | Type | Description
+---|:---:|---
+Callback name | [Callback Operation Object](#operationObject) | [Operation Object](#operationObject) | An operation object used to define a callback payload structure
+^x- | Any | Allows extensions to the OpenAPI Schema. The field name MUST begin with `x-`, for example, `x-internal-id`. The value can be `null`, a primitive, an array or an object. See [Specification Extensions](#specificationExtensions) for further details.
+
+
+##### Callback Object Example
+
+A callback to the URL specified by the `url` parameter in the request
+
+
+```yaml
+myWebhook:
+ '$request.url':
+ post:
+ body:
+ name: postResponse
+ schema:
+ $ref: '#/definitions/SomePayload'
+ responses:
+ 200:
+ description: webhook successfully processed an no retries will be performed
+```
+
+
#### Headers Object
Lists the headers that can be sent as part of a response.