diff --git a/message/message-formats.md b/message/message-formats.md
index f67afc7..1e7de50 100644
--- a/message/message-formats.md
+++ b/message/message-formats.md
@@ -4,12 +4,11 @@
 All **response** messages MUST support an [`application/hal+json`](http://stateless.co/hal_specification.html) (HAL) **based** format.
 
 ### Error Response Format
-Siren-based format MUST be used to communicate a problem (error). This format SHOULD be application or domain-specific accordingly to non-error response format.
+The [`application/vnd.error+json`](https://github.com/blongden/vnd.error) (vnd.error) MUST be used to communicate details about an error.
+
 
 ## Request Message Format
-Data body **request** messages MUST support a [`application/json`](http://www.json.org) (JSON) **based** format. 
-
-The JSON format MUST NOT be used **directly**, instead it MUST be used as the **base format** for every application or domain-specific format to convey specific semantics. E.g. `application/vnd.example+json`.
+Data body **request** messages SHOULD support a [`application/json`](http://www.json.org) (JSON) format. Where applicable the data body request message SHOULD also support the `application/hal+json` format.
 
 Data body **request** messages SHOULD also support the [`application/x-www-form-urlencoded`](https://tools.ietf.org/html/rfc1866#section-8.2.1) (URL Encoded) format.