diff --git a/spec.bs b/spec.bs
index 9e899fa..515ce54 100644
--- a/spec.bs
+++ b/spec.bs
@@ -1018,7 +1018,7 @@ A <dfn for=fencedframetype>destination event</dfn> is either a
 
        Note: The pending event will be sent asynchronously.
 
-  1. [=Assert=] that |reporting map|[|destination|] is a [=map=] (i.e. that |destination|'s
+  1. [=Assert=] that |reporting map|[|destination|] is a [=map=] (i.e., that |destination|'s
      metadata has been finalized).
 
   1. [=Send a beacon=] with |reporting map|[|destination|] and |event|.
@@ -1437,12 +1437,20 @@ the API {{Window/navigator}}.{{Navigator/deprecatedReplaceInURN()}}, which allow
 macros into the [=fenced frame config/mapped url=] corresponding to a given [=urn uuid=] or
 {{FencedFrameConfig}}.
 
+Note: To help with ease of adoption,
+[until third party cookie deprecation](https://developers.google.com/privacy-sandbox/relevance/protected-audience-api/feature-status#fenced_frames)
+we will support the API {{Window/navigator}}.{{Navigator/deprecatedURNtoURL()}}, which returns
+the [=fenced frame config/mapped url=] corresponding to a given [=urn uuid=] or
+{{FencedFrameConfig}}.
+
 <pre class=idl>
 typedef (USVString or FencedFrameConfig) UrnOrConfig;
 
 partial interface Navigator {
   Promise&lt;undefined&gt; deprecatedReplaceInURN(
     UrnOrConfig urnOrConfig, record&lt;USVString, USVString&gt; replacements);
+  Promise&lt;USVString&gt; deprecatedURNtoURL(
+    UrnOrConfig urnOrConfig, optional boolean send_reports = false);
   sequence&lt;USVString&gt; adAuctionComponents(unsigned short numAdComponents);
 };
 </pre>
@@ -1467,7 +1475,8 @@ partial interface Navigator {
 
   1. Otherwise, set |urn| to |urnOrConfig|'s [=fencedframeconfig/urn=].
 
-  1. If |urn| is <span class=XXX>TODO invalid</span>, [=exception/throw=] a {{TypeError}}.
+  1. If |urn| is not a valid [=urn uuid=] (i.e., won't pass the ABNF in Section 3 of
+     [=urn uuid=]), [=exception/throw=] a {{TypeError}}.
 
   1. [=map/For each=] |key| → _ of |replacements|:
      1. If |key| does not [=string/start with=] <code>${</code> or <code>%%</code>,
@@ -1481,7 +1490,7 @@ partial interface Navigator {
 
   1. Run the following steps [=in parallel=]:
 
-     1. Let |mapping| be |global|'s [=associated Document=]'s [=node navigable=]'s
+     1. Let |mapping| be |global|'s [=Window/navigable=]'s
         [=navigable/traversable navigable=]'s [=traversable navigable/fenced frame config mapping=].
 
      1. Let |config| be the result of [=fenced frame config mapping/finding a config=] in |mapping|
@@ -1507,7 +1516,47 @@ partial interface Navigator {
 </div>
 
 <div algorithm>
+  The <dfn method for=Navigator>deprecatedURNtoURL(|urnOrConfig|, |send_reports|)</dfn> method
+  steps are:
+
+  1. Let |urn| be null.
+
+  1. If |urnOrConfig| is a {{USVString}}, set |urn| to |urnOrConfig|.
+
+  1. Otherwise, set |urn| to |urnOrConfig|'s [=fencedframeconfig/urn=].
 
+  1. If |urn| is not a valid [=urn uuid=] (i.e., won't pass the ABNF in Section 3 of
+     [=urn uuid=]), [=exception/throw=] a {{TypeError}}.
+
+  1. Let |p| be [=a new promise=].
+
+  1. Let |global| be [=this=]'s [=relevant global object=].
+
+  1. Run the following steps [=in parallel=]:
+
+     1. Let |mapping| be |global|'s [=Window/navigable=]'s
+        [=navigable/traversable navigable=]'s [=traversable navigable/fenced frame config mapping=].
+
+     1. If |mapping|'s [=fenced frame config mapping/finalized config mapping=][|urn|], does not
+        [=map/exist=], then [=queue a global task=] on the [=DOM manipulation task source=]
+        given |global|, to [=resolve=] |p| with {{undefined}}, and abort these steps.
+
+     1. Let |config| be |mapping|'s [=fenced frame config mapping/finalized config mapping=][|urn|].
+
+     1. [=Queue a global task=] on the [=DOM manipulation task source=] given |global|, to
+        [=resolve=] |p| with |config|'s [=fenced frame config/mapped url=]'s [=mapped url/value=].
+
+     1. If |send_reports| is true, then run the steps in |config|'s
+        [=fenced frame config/on navigate callback=].
+
+  1. Return |p|.
+
+  <wpt>
+    /fenced-frame/deprecated-config-apis.https.html
+  </wpt>
+</div>
+
+<div algorithm>
   The <dfn method for=Navigator>adAuctionComponents(|numAdComponents|)</dfn>
   
   1. Let |instance| be [=this=]'s [=relevant global object=]'s [=Window/browsing context=]'s
@@ -1535,7 +1584,6 @@ partial interface Navigator {
      1. Set |numAdComponents| to |numAdComponents| &minus; 1.
 
   1. Return |adComponentsURNs|.
-
 </div>
 
 <h3 id=fence-interface>The {{Fence}} interface</h3>
@@ -1685,7 +1733,7 @@ Several APIs specific to fenced frames are defined on the {{Fence}} interface.
     /fenced-frame/fence-report-event-cross-origin-urn-iframe-no-embedder-opt-in.https.html 
     /fenced-frame/fence-report-event-cross-origin-urn-iframe-no-subframe-opt-in.https.html 
     /fenced-frame/fence-report-event-cross-origin-urn-iframe.https.html 
-    /fenced-frame/fence-report-event-cross-origin.https.html 
+    /fenced-frame/fence-report-event-cross-origin.sub.https.html 
     /fenced-frame/fence-report-event-sub-fencedframe.https.html 
   </wpt>
 </div>