---
schema_version: "1"
id: 283f4eed5946c97a384c9263e86a5c7ad5d64f8467c46a3f0f4ace3b0a71bf5c
title: Warning Header
collection: developer
version: current
locale: en-us
portal_url: https://docs.salesforce.com/developer/current/en-us/platform/api-rest/guides/headers/headers-warning.md
canonical_url: https://developer.salesforce.com/docs/platform/api-rest/guide/headers-warning.html
source_site: developer.salesforce.com
content_type: documentation
content_hash: a14bbe8de3559ba37bb348f3f6fae65bc65da93cf0fae488b7e37fb3159c1059
products:
  - REST API Developer Guide
  - Platform Developer Content
---

# Warning Header

This header is returned if there are warnings, such as the use of a deprecated version of the API.

## Header Field Name and Values

**Field name:** `Warning`

**Field Values:** `warningCode warningMessage` For warnings about deprecated API versions, the `warningCode` is `299`.

## Example

```nolang
Warning: 299 - "This API is deprecated and will be removed by Summer '22. Please see https://help.salesforce.com/articleView?id=000351312 for details." 
```