Require extensions to be JSON (fixes #357 and #270)

bvdh · kpshek · commit 8380c2b15b07 · 2018-07-11T10:47:11.000-05:00
diff --git a/docs/specification/1.0.md b/docs/specification/1.0.md
@@ -554,7 +554,7 @@ CDS Services and browser-based EHRs will require CORS support. A secure implemen
 
 ## Extensions
 
-The specification is not prescriptive about support for extensions. However, to support extensions, the specification reserves the name `extension` and will never define an element with that name, allowing implementations to use it to provide custom behavior and information. The value of an extension element should be a pre-coordinated JSON object.
+The specification is not prescriptive about support for extensions. However, to support extensions, the specification reserves the name `extension` and will never define an element with that name, allowing implementations to use it to provide custom behavior and information. The value of an extension element MUST be a pre-coordinated JSON object.
 
 For example, an extension on a request could look like this:
 
