diff --git a/css/elements.css b/css/elements.css
index 1811c092..f7e9f04f 100644
--- a/css/elements.css
+++ b/css/elements.css
@@ -1561,17 +1561,6 @@ li.menu-search-result-term::before {
   padding-right: 5px;
 }
 
-emu-normative-optional {
-  display: block;
-}
-
-emu-normative-optional::before {
-  display: block;
-  color: var(--attributes-tag-foreground-color);
-  content: "NORMATIVE OPTIONAL";
-}
-
-emu-normative-optional,
 [normative-optional],
 [deprecated],
 [legacy] {
diff --git a/css/print.css b/css/print.css
index ccce10d0..ba232de4 100644
--- a/css/print.css
+++ b/css/print.css
@@ -263,14 +263,6 @@ emu-alg ol li:last-child {
   break-after: initial; /* it's okay to break after the last item in a list, even if it's also the first item in the list */
 }
 
-emu-normative-optional emu-clause[id] {
-  margin-top: 0;
-}
-
-emu-normative-optional emu-alg > ol {
-  margin-bottom: 0;
-}
-
 emu-note {
   gap: initial;
   justify-content: space-between;
diff --git a/src/lint/collect-tag-diagnostics.ts b/src/lint/collect-tag-diagnostics.ts
index 90daa8d3..69620609 100644
--- a/src/lint/collect-tag-diagnostics.ts
+++ b/src/lint/collect-tag-diagnostics.ts
@@ -27,7 +27,6 @@ const knownEmuTags = new Set([
   'emu-gann',
   'emu-gprose',
   'emu-gmod',
-  'emu-normative-optional', // used in ecma-402
 ]);
 
 // https://html.spec.whatwg.org/multipage/syntax.html#void-elements
diff --git a/test/baselines/generated-reference/assets-inline.html b/test/baselines/generated-reference/assets-inline.html
index 7cb4754b..b724cfd6 100644
--- a/test/baselines/generated-reference/assets-inline.html
+++ b/test/baselines/generated-reference/assets-inline.html
@@ -3173,17 +3173,6 @@
   padding-right: 5px;
 }
 
-emu-normative-optional {
-  display: block;
-}
-
-emu-normative-optional::before {
-  display: block;
-  color: var(--attributes-tag-foreground-color);
-  content: "NORMATIVE OPTIONAL";
-}
-
-emu-normative-optional,
 [normative-optional],
 [deprecated],
 [legacy] {
@@ -3511,14 +3500,6 @@
   break-after: initial; /* it's okay to break after the last item in a list, even if it's also the first item in the list */
 }
 
-emu-normative-optional emu-clause[id] {
-  margin-top: 0;
-}
-
-emu-normative-optional emu-alg > ol {
-  margin-bottom: 0;
-}
-
 emu-note {
   gap: initial;
   justify-content: space-between;