diff --git a/source b/source
index 4c1d6626a3e..618062dee86 100644
--- a/source
+++ b/source
@@ -8945,7 +8945,7 @@ partial /*sealed*/ interface <dfn>Document</dfn> {
   attribute DOMString <span data-x="dom-accessKey">accessKey</span>;
   readonly attribute DOMString <span data-x="dom-accessKeyLabel">accessKeyLabel</span>;
   attribute boolean <span data-x="dom-draggable">draggable</span>;
-  [PutForwards=<span data-x="dom-DOMTokenList-value">value</span>] readonly attribute <span>DOMTokenList</span> <span data-x="dom-dropzone">dropzone</span>;
+  [SameObject, PutForwards=<span data-x="dom-DOMTokenList-value">value</span>] readonly attribute <span>DOMTokenList</span> <span data-x="dom-dropzone">dropzone</span>;
   attribute <span>HTMLMenuElement</span>? <span data-x="dom-contextMenu">contextMenu</span>;
   attribute boolean <span data-x="dom-spellcheck">spellcheck</span>;
   void <span data-x="dom-forceSpellCheck">forceSpellCheck</span>();
@@ -11536,11 +11536,11 @@ gave me some of the songs they wrote. I love sharing my music.&lt;/p>
   attribute DOMString <span data-x="dom-link-href">href</span>;
   attribute DOMString? <span data-x="dom-link-crossOrigin">crossOrigin</span>;
   attribute DOMString <span data-x="dom-link-rel">rel</span>;
-  [PutForwards=<span data-x="dom-DOMTokenList-value">value</span>] readonly attribute <span>DOMTokenList</span> <span data-x="dom-link-relList">relList</span>;
+  [SameObject, PutForwards=<span data-x="dom-DOMTokenList-value">value</span>] readonly attribute <span>DOMTokenList</span> <span data-x="dom-link-relList">relList</span>;
   attribute DOMString <span data-x="dom-link-media">media</span>;
   attribute DOMString <span data-x="dom-link-hreflang">hreflang</span>;
   attribute DOMString <span data-x="dom-link-type">type</span>;
-  [PutForwards=<span data-x="dom-DOMTokenList-value">value</span>] readonly attribute <span>DOMTokenList</span> <span data-x="dom-link-sizes">sizes</span>;
+  [SameObject, PutForwards=<span data-x="dom-DOMTokenList-value">value</span>] readonly attribute <span>DOMTokenList</span> <span data-x="dom-link-sizes">sizes</span>;
 };
 <span>HTMLLinkElement</span> implements <span>LinkStyle</span>;</pre>
    </dd>
@@ -17187,9 +17187,9 @@ included with Exhibit B.
 <pre class="idl">interface <dfn>HTMLAnchorElement</dfn> : <span>HTMLElement</span> {
   attribute DOMString <span data-x="dom-a-target">target</span>;
   attribute DOMString <span data-x="dom-a-download">download</span>;
-  [PutForwards=<span data-x="dom-DOMTokenList-value">value</span>] readonly attribute <span>DOMTokenList</span> <span data-x="dom-a-ping">ping</span>;
+  [SameObject, PutForwards=<span data-x="dom-DOMTokenList-value">value</span>] readonly attribute <span>DOMTokenList</span> <span data-x="dom-a-ping">ping</span>;
   attribute DOMString <span data-x="dom-a-rel">rel</span>;
-  [PutForwards=<span data-x="dom-DOMTokenList-value">value</span>] readonly attribute <span>DOMTokenList</span> <span data-x="dom-a-relList">relList</span>;
+  [SameObject, PutForwards=<span data-x="dom-DOMTokenList-value">value</span>] readonly attribute <span>DOMTokenList</span> <span data-x="dom-a-relList">relList</span>;
   attribute DOMString <span data-x="dom-a-hreflang">hreflang</span>;
   attribute DOMString <span data-x="dom-a-type">type</span>;
 
@@ -26386,7 +26386,7 @@ href="?audio">audio&lt;/a> test instead.)&lt;/p></pre>
   attribute DOMString <span data-x="dom-iframe-src">src</span>;
   attribute DOMString <span data-x="dom-iframe-srcdoc">srcdoc</span>;
   attribute DOMString <span data-x="dom-iframe-name">name</span>;
-  [PutForwards=<span data-x="dom-DOMTokenList-value">value</span>] readonly attribute <span>DOMTokenList</span> <span data-x="dom-iframe-sandbox">sandbox</span>;
+  [SameObject, PutForwards=<span data-x="dom-DOMTokenList-value">value</span>] readonly attribute <span>DOMTokenList</span> <span data-x="dom-iframe-sandbox">sandbox</span>;
   attribute boolean <span data-x="dom-iframe-allowFullscreen">allowFullscreen</span>;
   attribute DOMString <span data-x="dom-dim-width">width</span>;
   attribute DOMString <span data-x="dom-dim-height">height</span>;
@@ -36764,9 +36764,9 @@ dictionary <dfn>TrackEventInit</dfn> : <span>EventInit</span> {
   attribute DOMString <span data-x="dom-area-shape">shape</span>;
   attribute DOMString <span data-x="dom-area-target">target</span>;
   attribute DOMString <span data-x="dom-area-download">download</span>;
-  [PutForwards=<span data-x="dom-DOMTokenList-value">value</span>] readonly attribute <span>DOMTokenList</span> <span data-x="dom-area-ping">ping</span>;
+  [SameObject, PutForwards=<span data-x="dom-DOMTokenList-value">value</span>] readonly attribute <span>DOMTokenList</span> <span data-x="dom-area-ping">ping</span>;
   attribute DOMString <span data-x="dom-area-rel">rel</span>;
-  [PutForwards=<span data-x="dom-DOMTokenList-value">value</span>] readonly attribute <span>DOMTokenList</span> <span data-x="dom-area-relList">relList</span>;
+  [SameObject, PutForwards=<span data-x="dom-DOMTokenList-value">value</span>] readonly attribute <span>DOMTokenList</span> <span data-x="dom-area-relList">relList</span>;
 };
 <span>HTMLAreaElement</span> implements <span>HTMLHyperlinkElementUtils</span>;</pre>
    </dd>
@@ -38987,7 +38987,7 @@ the cell that corresponds to the values of the two dice.
   <pre class="idl">interface <dfn>HTMLTableCellElement</dfn> : <span>HTMLElement</span> {
   attribute unsigned long <span data-x="dom-tdth-colSpan">colSpan</span>;
   attribute unsigned long <span data-x="dom-tdth-rowSpan">rowSpan</span>;
-  [PutForwards=<span data-x="dom-DOMTokenList-value">value</span>] readonly attribute <span>DOMTokenList</span> <span data-x="dom-tdth-headers">headers</span>;
+  [SameObject, PutForwards=<span data-x="dom-DOMTokenList-value">value</span>] readonly attribute <span>DOMTokenList</span> <span data-x="dom-tdth-headers">headers</span>;
   readonly attribute long <span data-x="dom-tdth-cellIndex">cellIndex</span>;
 };</pre>
 
@@ -50110,7 +50110,7 @@ Daddy">&lt;/textarea></pre>
    <dt><span data-x="concept-element-dom">DOM interface</span>:</dt><!--TOPIC:DOM APIs-->
    <dd>
 <pre class="idl">interface <dfn>HTMLOutputElement</dfn> : <span>HTMLElement</span> {
-  [PutForwards=<span data-x="dom-DOMTokenList-value">value</span>] readonly attribute <span>DOMTokenList</span> <span data-x="dom-output-htmlFor">htmlFor</span>;
+  [SameObject, PutForwards=<span data-x="dom-DOMTokenList-value">value</span>] readonly attribute <span>DOMTokenList</span> <span data-x="dom-output-htmlFor">htmlFor</span>;
   readonly attribute <span>HTMLFormElement</span>? <span data-x="dom-fae-form">form</span>;
   attribute DOMString <span data-x="dom-fe-name">name</span>;