diff --git a/css/selectors/after.json b/css/selectors/after.json
index fee764b54b52ba..39ee5662a9b025 100644
--- a/css/selectors/after.json
+++ b/css/selectors/after.json
@@ -137,6 +137,41 @@
               "deprecated": false
             }
           }
+        },
+        "nested_marker": {
+          "__compat": {
+            "description": "`::after::marker` nested pseudo-elements",
+            "spec_url": "https://www.w3.org/TR/css-pseudo-4/#:~:text=The%20::before::marker%20or%20::after::marker%20selectors",
+            "support": {
+              "chrome": {
+                "version_added": "135"
+              },
+              "chrome_android": "mirror",
+              "edge": "mirror",
+              "firefox": {
+                "version_added": false
+              },
+              "firefox_android": "mirror",
+              "ie": {
+                "version_added": false
+              },
+              "oculus": "mirror",
+              "opera": "mirror",
+              "opera_android": "mirror",
+              "safari": {
+                "version_added": false
+              },
+              "safari_ios": "mirror",
+              "samsunginternet_android": "mirror",
+              "webview_android": "mirror",
+              "webview_ios": "mirror"
+            },
+            "status": {
+              "experimental": true,
+              "standard_track": true,
+              "deprecated": false
+            }
+          }
         }
       }
     }
diff --git a/css/selectors/before.json b/css/selectors/before.json
index ac141379ab6cb1..a805520e6161cb 100644
--- a/css/selectors/before.json
+++ b/css/selectors/before.json
@@ -154,6 +154,41 @@
               "deprecated": false
             }
           }
+        },
+        "nested_marker": {
+          "__compat": {
+            "description": "`::before::marker` nested pseudo-elements",
+            "spec_url": "https://www.w3.org/TR/css-pseudo-4/#:~:text=The%20::before::marker%20or%20::after::marker%20selectors",
+            "support": {
+              "chrome": {
+                "version_added": "135"
+              },
+              "chrome_android": "mirror",
+              "edge": "mirror",
+              "firefox": {
+                "version_added": false
+              },
+              "firefox_android": "mirror",
+              "ie": {
+                "version_added": false
+              },
+              "oculus": "mirror",
+              "opera": "mirror",
+              "opera_android": "mirror",
+              "safari": {
+                "version_added": false
+              },
+              "safari_ios": "mirror",
+              "samsunginternet_android": "mirror",
+              "webview_android": "mirror",
+              "webview_ios": "mirror"
+            },
+            "status": {
+              "experimental": true,
+              "standard_track": true,
+              "deprecated": false
+            }
+          }
         }
       }
     }