diff --git a/specs.json b/specs.json
index c59257e3..21f3d132 100644
--- a/specs.json
+++ b/specs.json
@@ -305,6 +305,16 @@
   },
   "https://tc39.es/proposal-array-from-async/",
   "https://tc39.es/proposal-array-grouping/",
+  {
+    "url": "https://tc39.es/proposal-arraybuffer-base64/spec/",
+    "series": {
+      "shortname": "tc39-arraybuffer-base64"
+    },
+    "shortname": "tc39-arraybuffer-base64",
+    "nightly": {
+      "sourcePath": "spec.html"
+    }
+  },
   "https://tc39.es/proposal-arraybuffer-transfer/",
   "https://tc39.es/proposal-async-explicit-resource-management/",
   {
@@ -578,6 +588,7 @@
   "https://wicg.github.io/datacue/",
   "https://wicg.github.io/deprecation-reporting/",
   "https://wicg.github.io/digital-goods/",
+  "https://wicg.github.io/digital-identities/",
   "https://wicg.github.io/direct-sockets/",
   "https://wicg.github.io/document-picture-in-picture/",
   "https://wicg.github.io/document-policy/",
diff --git a/src/compute-shortname.js b/src/compute-shortname.js
index 9495d3fd..d66915f8 100644
--- a/src/compute-shortname.js
+++ b/src/compute-shortname.js
@@ -177,7 +177,8 @@ function completeWithSeriesAndLevel(shortname, url, forkOf) {
   // typically have the form "ecma-ddd", and "ddd" is *not* a level number.
   // And that's the same for ISO standards which end with plenty of non-level
   // digits, as in "iso18181-2".
-  if (seriesBasename.match(/^ecma-/) ||
+  if (seriesBasename.startsWith("ecma-") ||
+      seriesBasename.startsWith("tc39-") ||
       seriesBasename.startsWith("iso") ||
       url.match(/^https:\/\/registry\.khronos\.org\/webgl\/extensions\//)) {
     return {
@@ -188,7 +189,7 @@ function completeWithSeriesAndLevel(shortname, url, forkOf) {
 
   // Extract X and X.Y levels, with form "name-X" or "name-X.Y".
   // (e.g. 5 for "mediaqueries-5", 1.2 for "wai-aria-1.2")
-  let match = seriesBasename.match(/^(.*?)-v?(\d+)(.\d+)?$/);
+  let match = seriesBasename.match(/^(.*?)-v?(\d+)(\.\d+)?$/);
   if (match) {
     return {
       shortname: specShortname,
diff --git a/src/data/ignore.json b/src/data/ignore.json
index a7583486..342efd28 100644
--- a/src/data/ignore.json
+++ b/src/data/ignore.json
@@ -83,6 +83,9 @@
     "WICG/close-watcher": {
       "comment": "merged into HTML"
     },
+    "WICG/discourse-archive": {
+      "comment": "not a spec"
+    },
     "WICG/priority-hints": {
       "comment": "merged into HTML"
     },
diff --git a/test/compute-shortname.js b/test/compute-shortname.js
index 871cf5f3..e24ac766 100644
--- a/test/compute-shortname.js
+++ b/test/compute-shortname.js
@@ -246,6 +246,10 @@ describe("compute-shortname module", () => {
       assertNoSeriesVersion("ecma-402");
     });
 
+    it("does not confuse a TC39 proposal number with a series version", () => {
+      assertNoSeriesVersion("tc39-arraybuffer-base64");
+    });
+
     it("does not confuse an ISO spec number with a series version", () => {
       assertNoSeriesVersion("iso18181-2");
     });