--- a/spec/latest/json-ld-api/index.html	Wed Mar 13 19:23:44 2013 +0100
+++ b/spec/latest/json-ld-api/index.html	Wed Mar 13 19:34:04 2013 +0100
@@ -608,11 +608,11 @@
 
   <dl>
     <dt><tdef>JSON object</tdef></dt>
-    <dd>An object structure is represented as a pair of curly brackets
-      surrounding zero or more key-value pairs. A key is a
-      <tref>string</tref>. A single colon comes after each key, separating the
-      key from the value. A single comma separates a value from a following
-      key.</dd>
+    <dd>An object structure is represented as a pair of curly brackets surrounding
+      zero or more key-value pairs. A key is a <tref>string</tref>.
+      A single colon comes after each key, separating the key from the value.
+      A single comma separates a value from a following key. In contrast to JSON,
+      in JSON-LD the keys in an object must be unique.</dd>
     <dt><tdef>array</tdef></dt>
     <dd>An array structure is represented as square brackets surrounding zero
       or more values (or elements). Elements are separated by commas.
@@ -754,8 +754,8 @@
       <ul>
         <li>it does not contain the <code>@value</code>, <code>@list</code>,
           or <code>@set</code> keywords, or</li>
-        <li>it is not the top-level <tref>JSON object</tref> in the JSON-LD document containing
-          the <code>@graph</code> keyword.</li>
+        <li>it is not the top-most <tref>JSON object</tref> in the JSON-LD document consisting
+          of no other members than <code>@graph</code> and <code>@context</code>.</li>
       </ul>
     </dd>
     <dt><tdef>value object</tdef></dt>