diff --git a/ed/diff.md b/ed/diff.md
index d38236ab1018..5a65d2b81509 100644
--- a/ed/diff.md
+++ b/ed/diff.md
@@ -1,4 +1,4 @@
-% Diff between report from "April 12, 2021" and reference report from "April 11, 2021"
+% Diff between report from "April 12, 2021" and reference report from "April 12, 2021"
 % Reffy
 % April 12, 2021
 
diff --git a/ed/diffnew.md b/ed/diffnew.md
index d38236ab1018..5a65d2b81509 100644
--- a/ed/diffnew.md
+++ b/ed/diffnew.md
@@ -1,4 +1,4 @@
-% Diff between report from "April 12, 2021" and reference report from "April 11, 2021"
+% Diff between report from "April 12, 2021" and reference report from "April 12, 2021"
 % Reffy
 % April 12, 2021
 
diff --git a/ed/headings/fetch.json b/ed/headings/fetch.json
index 1f28fa848a6b..8acd08710468 100644
--- a/ed/headings/fetch.json
+++ b/ed/headings/fetch.json
@@ -12,7 +12,7 @@
     {
       "id": "subtitle",
       "level": 2,
-      "title": "Living Standard — Last Updated 31 March 2021"
+      "title": "Living Standard — Last Updated 11 April 2021"
     },
     {
       "id": "abstract",
diff --git a/ed/ids/fetch.json b/ed/ids/fetch.json
index 15c6a8019f64..e9064621ec7d 100644
--- a/ed/ids/fetch.json
+++ b/ed/ids/fetch.json
@@ -1046,7 +1046,6 @@
     "ref-for-concept-url-scheme⑤",
     "ref-for-concept-url-host",
     "ref-for-concept-url-port②",
-    "ref-for-concept-header③⑤",
     "append-a-request-origin-header",
     "ref-for-concept-request⑦①",
     "ref-for-byte-serializing-a-request-origin",
@@ -1097,20 +1096,20 @@
     "ref-for-cors-request①",
     "ref-for-cors-protocol⑦",
     "ref-for-concept-method⑥",
-    "ref-for-concept-header③⑥",
+    "ref-for-concept-header③⑤",
     "http-access-control-request-method",
     "ref-for-concept-method⑦",
     "ref-for-cors-request②",
     "http-access-control-request-headers",
-    "ref-for-concept-header③⑦",
+    "ref-for-concept-header③⑥",
     "ref-for-cors-request③",
     "http-responses",
     "ref-for-cors-request④",
-    "ref-for-concept-header③⑧",
+    "ref-for-concept-header③⑦",
     "http-access-control-allow-origin",
     "ref-for-concept-header-value②⑥",
     "ref-for-http-origin⑤",
-    "ref-for-concept-header③⑨",
+    "ref-for-concept-header③⑧",
     "http-access-control-allow-credentials",
     "ref-for-concept-request⑦⑦",
     "ref-for-concept-request-credentials-mode②",
@@ -1120,38 +1119,38 @@
     "ref-for-cors-request⑤",
     "ref-for-cors-preflight-request③",
     "ref-for-cors-preflight-request④",
-    "ref-for-concept-header④⓪",
+    "ref-for-concept-header③⑨",
     "http-access-control-allow-methods",
     "ref-for-concept-method⑧",
     "ref-for-concept-response③③",
     "ref-for-concept-response-url③",
     "ref-for-cors-protocol⑧",
-    "ref-for-concept-header④①",
+    "ref-for-concept-header④⓪",
     "ref-for-cors-protocol⑨",
     "http-access-control-allow-headers",
-    "ref-for-concept-header④②",
+    "ref-for-concept-header④①",
     "ref-for-concept-response③④",
     "ref-for-concept-response-url④",
     "ref-for-cors-protocol①⓪",
     "http-access-control-max-age",
     "ref-for-http-access-control-allow-methods",
     "ref-for-http-access-control-allow-headers",
-    "ref-for-concept-header④③",
+    "ref-for-concept-header④②",
     "ref-for-cors-request⑥",
     "ref-for-cors-preflight-request⑤",
-    "ref-for-concept-header④④",
+    "ref-for-concept-header④③",
     "http-access-control-expose-headers",
-    "ref-for-concept-header④⑤",
+    "ref-for-concept-header④④",
     "ref-for-concept-header-name④①",
     "ref-for-cors-protocol①①",
     "ref-for-cors-request⑦",
     "ref-for-cors-preflight-request⑥",
-    "ref-for-concept-header④⑥",
+    "ref-for-concept-header④⑤",
     "ref-for-concept-status④",
     "http-new-header-syntax",
     "ref-for-abnf④",
     "ref-for-concept-header-value②⑦",
-    "ref-for-concept-header④⑦",
+    "ref-for-concept-header④⑥",
     "ref-for-cors-protocol①②",
     "ref-for-section-3.1.1①",
     "ref-for-section-3.2①",
@@ -1159,12 +1158,12 @@
     "ref-for-section-1.2.1",
     "ref-for-section-3.1.1②",
     "ref-for-section-3.2③",
-    "ref-for-concept-header④⑧",
+    "ref-for-concept-header④⑦",
     "ref-for-concept-header-value②⑧",
     "ref-for-concept-request⑦⑨",
     "ref-for-credentials②",
     "ref-for-concept-request⑧⓪",
-    "ref-for-concept-header④⑨",
+    "ref-for-concept-header④⑧",
     "ref-for-concept-header-name④②",
     "ref-for-concept-method⑨",
     "cors-protocol-and-credentials",
@@ -1192,7 +1191,7 @@
     "ref-for-credentials①⓪",
     "ref-for-http-access-control-allow-origin",
     "ref-for-http-access-control-allow-credentials",
-    "ref-for-concept-header⑤⓪",
+    "ref-for-concept-header④⑨",
     "ref-for-http-access-control-allow-origin①",
     "ref-for-http-access-control-allow-credentials①",
     "ref-for-http-access-control-allow-credentials②",
@@ -1260,9 +1259,9 @@
     "ref-for-serialize-a-mime-type",
     "x-content-type-options-header",
     "http-x-content-type-options",
-    "ref-for-concept-header⑤①",
+    "ref-for-concept-header⑤⓪",
     "ref-for-concept-response③⑤",
-    "ref-for-concept-header⑤②",
+    "ref-for-concept-header⑤①",
     "ref-for-concept-request-destination⑨",
     "ref-for-concept-request⑧⑦",
     "determine-nosniff",
@@ -1312,7 +1311,7 @@
     "ref-for-mime-type③",
     "cross-origin-resource-policy-header",
     "http-cross-origin-resource-policy",
-    "ref-for-concept-header⑤③",
+    "ref-for-concept-header⑤②",
     "ref-for-concept-request⑧⑨",
     "ref-for-concept-request-current-url⑥",
     "ref-for-concept-url-origin②",
@@ -1539,11 +1538,11 @@
     "ref-for-concept-response-header-list①④",
     "ref-for-concept-request-credentials-mode⑧",
     "ref-for-concept-response-cors-exposed-header-name-list③",
-    "ref-for-concept-header⑤④",
+    "ref-for-concept-header⑤③",
     "ref-for-concept-header-name④③",
     "ref-for-concept-response-header-list①⑤",
     "ref-for-concept-response-cors-exposed-header-name-list④",
-    "ref-for-concept-header⑤⑤",
+    "ref-for-concept-header⑤④",
     "ref-for-concept-header-name④④",
     "ref-for-concept-filtered-response①⓪",
     "ref-for-concept-internal-response⑨",
@@ -1650,7 +1649,7 @@
     "ref-for-concept-response④⑧",
     "ref-for-concept-response-status-message③",
     "ref-for-concept-response-header-list①⑥",
-    "ref-for-concept-header⑤⑥",
+    "ref-for-concept-header⑤⑤",
     "ref-for-concept-header-name④⑤",
     "ref-for-concept-header-value③②",
     "ref-for-concept-response-body①④",
@@ -1687,7 +1686,7 @@
     "ref-for-concept-response⑤⓪",
     "ref-for-concept-response-status-message⑤",
     "ref-for-concept-response-header-list①⑨",
-    "ref-for-concept-header⑤⑦",
+    "ref-for-concept-header⑤⑥",
     "ref-for-concept-header-name④⑥",
     "ref-for-concept-header-value③③",
     "ref-for-data-url-struct-mime-type",
@@ -1943,12 +1942,12 @@
     "ref-for-concept-response⑤⑥",
     "ref-for-concept-request-header-list②⑥",
     "ref-for-concept-header-list-append①④",
-    "ref-for-concept-header⑤⑧",
+    "ref-for-concept-header⑤⑦",
     "ref-for-concept-request-header-list②⑦",
     "ref-for-header-list-contains①⑦",
-    "ref-for-concept-header⑤⑨",
+    "ref-for-concept-header⑤⑧",
     "ref-for-concept-header-name④⑦",
-    "ref-for-concept-header⑥⓪",
+    "ref-for-concept-header⑤⑨",
     "ref-for-concept-header-list-append①⑤",
     "ref-for-dom-global-fetch③",
     "ref-for-http-header-layer-division",
@@ -1972,7 +1971,7 @@
     "ref-for-concept-request-cache-mode⑤",
     "ref-for-concept-request-cache-mode⑥",
     "ref-for-fetch-params-timing-info⑤",
-    "ref-for-concept-header⑥①",
+    "ref-for-concept-header⑥⓪",
     "ref-for-concept-request-cache-mode⑦",
     "ref-for-concept-stale-while-revalidate-response②",
     "ref-for-concept-request-client①⑥",
@@ -2093,7 +2092,7 @@
     "ref-for-fetch-timing-info-final-network-response-start-time",
     "ref-for-dfn-coarsened-shared-current-time⑤",
     "ref-for-fetch-params-cross-origin-isolated-capability⑤",
-    "ref-for-concept-header⑥②",
+    "ref-for-concept-header⑥①",
     "ref-for-concept-response⑤⑦",
     "ref-for-concept-response-status②①",
     "ref-for-fetch-timing-info-final-network-response-start-time①",
@@ -2163,7 +2162,7 @@
     "ref-for-fetch-timing-info-encoded-body-size②",
     "ref-for-byte-sequence-length③",
     "ref-for-handle-content-codings①",
-    "ref-for-concept-header⑥③",
+    "ref-for-concept-header⑥②",
     "ref-for-fetch-timing-info-decoded-body-size②",
     "ref-for-byte-sequence-length④",
     "ref-for-concept-fetch-terminate①⑥",
@@ -2301,7 +2300,7 @@
     "concept-cache-method",
     "ref-for-concept-method①①",
     "concept-cache-header-name",
-    "ref-for-concept-header⑥④",
+    "ref-for-concept-header⑥③",
     "ref-for-concept-header-name⑤⓪",
     "ref-for-cache-entry①",
     "ref-for-concept-cache-max-age③",
@@ -2424,7 +2423,7 @@
     "ref-for-idl-ByteString①②",
     "ref-for-concept-header-list②⓪",
     "ref-for-headers",
-    "ref-for-concept-header⑥⑤",
+    "ref-for-concept-header⑥④",
     "ref-for-headers①",
     "ref-for-concept-header-list②①",
     "ref-for-headers②",
@@ -3579,7 +3578,7 @@
     "ref-for-concept-request-header-list⑤⓪",
     "ref-for-concept-header-list-combine②",
     "ref-for-concept-request-header-list⑤①",
-    "ref-for-concept-header⑥⑥",
+    "ref-for-concept-header⑥⑤",
     "ref-for-concept-header-value④①",
     "example-permessage-deflate",
     "ref-for-concept-header-list-append③⓪",
@@ -3639,10 +3638,10 @@
     "basic-safe-cors-protocol-setup",
     "ref-for-cors-protocol②⓪",
     "ref-for-cors-protocol②①",
+    "ref-for-concept-header⑥⑥",
     "ref-for-concept-header⑥⑦",
-    "ref-for-concept-header⑥⑧",
     "ref-for-xmlhttprequest⑧",
-    "ref-for-concept-header⑥⑨",
+    "ref-for-concept-header⑥⑧",
     "cors-protocol-and-http-caches",
     "ref-for-cors-protocol②②",
     "ref-for-http-access-control-allow-origin⑦",
diff --git a/ed/ids/webrtc-identity.json b/ed/ids/webrtc-identity.json
index fade01a66cde..0d74a70eb77d 100644
--- a/ed/ids/webrtc-identity.json
+++ b/ed/ids/webrtc-identity.json
@@ -126,7 +126,7 @@
     "sec.idp-error-handling",
     "rtcpeerconnection-interface-extensions",
     "x9-rtcpeerconnection-interface-extensions",
-    "idl-5562971949903059",
+    "idl-6239094558367431",
     "attributes-1",
     "dfn-peeridentity",
     "dfn-idploginurl",
@@ -155,7 +155,7 @@
     "rtcidentityassertion-interface",
     "x9-3-rtcidentityassertion-interface",
     "dfn-rtcidentityassertion",
-    "idl-3716426503168526",
+    "idl-6775679674227255",
     "rtcidentityassertion-attributes",
     "dfn-idp",
     "dfn-name",
@@ -170,20 +170,20 @@
     "target-peer-identity",
     "rtcerror-interface-extensions",
     "x10-rtcerror-interface-extensions",
-    "idl-43269154408734045",
+    "idl-6516806576856733",
     "attributes",
     "x10-1-attributes",
     "dfn-httprequeststatuscode",
     "rtcerrorinit-dictionary",
     "dfn-rtcerrorinit",
-    "idl-1851748370111228",
+    "idl-01152968840695845",
     "dfn-httprequeststatuscode-0",
     "dictionary-rtcerror-members",
     "x10-2-dictionary-rtcerror-members",
     "rtcerrordetailtypeidp-enum",
     "x10-3-rtcerrordetailtypeidp-enum",
     "dfn-rtcerrordetailtypeidp",
-    "idl-2916815332296603",
+    "idl-2884747898174207",
     "dfn-idp-bad-script-failure",
     "dfn-idp-execution-failure",
     "dfn-idp-load-failure",
@@ -196,13 +196,13 @@
     "x11-media-stream-api-extensions-for-network-use",
     "isolated-media-streams",
     "x11-1-isolated-media-streams",
-    "idl-17536440918165597",
+    "idl-07391802676745107",
     "dictionary-mediastreamconstraints-members",
     "dfn-peeridentity-0",
     "dfn-peeridentity-1",
     "isolated-track",
     "x11-1-1-extended-mediastreamtrack-properties",
-    "idl-6503127516295717",
+    "idl-2674006369220676",
     "attributes-2",
     "dfn-isolated",
     "dfn-onisolationchange",
diff --git a/ed/index.html b/ed/index.html
index 0bb42eee15eb..fb050be6cdc8 100644
--- a/ed/index.html
+++ b/ed/index.html
@@ -8663,7 +8663,7 @@ <h3>Spec info</h3>
   <ul>
   <li>Initial URL: <a href="https://fetch.spec.whatwg.org/" class="uri">https://fetch.spec.whatwg.org/</a></li>
   <li>Crawled URL: <a href="https://fetch.spec.whatwg.org/" class="uri">https://fetch.spec.whatwg.org/</a></li>
-  <li>Crawled version: 31 March 2021</li>
+  <li>Crawled version: 11 April 2021</li>
   <li>Editor's Draft: <a href="https://fetch.spec.whatwg.org/" class="uri">https://fetch.spec.whatwg.org/</a></li>
   <li>Shortname: fetch</li>
   </ul>
diff --git a/ed/index.json b/ed/index.json
index 286ca2313752..0125cc9863f3 100644
--- a/ed/index.json
+++ b/ed/index.json
@@ -1,7 +1,7 @@
 {
   "type": "crawl",
   "title": "Reffy crawl",
-  "date": "2021-04-12T00:51:54.864Z",
+  "date": "2021-04-12T06:45:10.557Z",
   "options": {},
   "stats": {
     "crawled": 387,
@@ -784,7 +784,7 @@
         "https://fetch.spec.whatwg.org/"
       ],
       "crawled": "https://fetch.spec.whatwg.org/",
-      "date": "31 March 2021",
+      "date": "11 April 2021",
       "links": "links/fetch.json",
       "refs": "refs/fetch.json",
       "idl": "idl/fetch.idl",
diff --git a/ed/index.md b/ed/index.md
index 2d515b24e7f4..3aeb2b58ec8c 100644
--- a/ed/index.md
+++ b/ed/index.md
@@ -7164,7 +7164,7 @@ Informative references to this spec from:
 
 - Initial URL: [https://fetch.spec.whatwg.org/](https://fetch.spec.whatwg.org/)
 - Crawled URL: [https://fetch.spec.whatwg.org/](https://fetch.spec.whatwg.org/)
-- Crawled version: 31 March 2021
+- Crawled version: 11 April 2021
 - Editor's Draft: [https://fetch.spec.whatwg.org/](https://fetch.spec.whatwg.org/)
 - Shortname: fetch
 
diff --git a/ed/study.json b/ed/study.json
index 05b8e91ea996..f754e197fdc4 100644
--- a/ed/study.json
+++ b/ed/study.json
@@ -2,7 +2,7 @@
   "type": "study",
   "title": "Reffy crawl",
   "description": "",
-  "date": "2021-04-12T00:51:54.864Z",
+  "date": "2021-04-12T06:45:10.557Z",
   "stats": {
     "crawled": 387,
     "errors": 0,
@@ -19556,7 +19556,7 @@
     {
       "title": "Fetch Standard",
       "shortname": "fetch",
-      "date": "31 March 2021",
+      "date": "11 April 2021",
       "url": "https://fetch.spec.whatwg.org/",
       "nightly": {
         "url": "https://fetch.spec.whatwg.org/",