diff --git a/.eslint-doc-generatorrc.js b/.eslint-doc-generatorrc.js
index 5d998d56c7..0e0a125a31 100644
--- a/.eslint-doc-generatorrc.js
+++ b/.eslint-doc-generatorrc.js
@@ -1,3 +1,10 @@
+const path = require('path');
+
+const HBS_ONLY_NOTE =
+  '> **HBS Only**: This rule applies to classic `.hbs` template files only (loose mode). It is not relevant for `gjs`/`gts` files (strict mode), where these patterns cannot occur.';
+
+const END_HEADER_MARKER = '<!-- end auto-generated rule header -->';
+
 /** @type {import('eslint-doc-generator').GenerateOptions} */
 module.exports = {
   configEmoji: [
@@ -8,4 +15,29 @@ module.exports = {
   ruleDocTitleFormat: 'prefix-name',
   ruleListSplit: 'meta.docs.category',
   urlConfigs: 'https://github.com/ember-cli/eslint-plugin-ember#-configurations',
+  postprocess(content, filePath) {
+    // Only process rule doc files
+    if (!filePath.includes(path.join('docs', 'rules'))) {
+      return content;
+    }
+
+    const ruleName = path.basename(filePath, '.md');
+
+    let rule;
+    try {
+      rule = require(path.join(__dirname, 'lib', 'rules', ruleName));
+    } catch {
+      return content;
+    }
+
+    // Strip any existing HBS Only note (with surrounding blank lines)
+    let result = content.replace(/\n> \*\*HBS Only\*\*:[^\n]+\n/, '\n');
+
+    // Add HBS Only note for loose-mode rules
+    if (rule.meta?.docs?.templateMode === 'loose') {
+      result = result.replace(END_HEADER_MARKER, `${HBS_ONLY_NOTE}\n\n${END_HEADER_MARKER}`);
+    }
+
+    return result;
+  },
 };