diff --git a/css/types/attr.json b/css/types/attr.json
index 0bf6294582250d..3bf5a4b15b5ae1 100644
--- a/css/types/attr.json
+++ b/css/types/attr.json
@@ -45,9 +45,10 @@
             "deprecated": false
           }
         },
-        "fallback": {
+        "declaration-value": {
           "__compat": {
-            "description": "<fallback>",
+            "description": "`<declaration-value>`",
+            "spec_url": "https://drafts.csswg.org/css-values-5/#ref-for-typedef-declaration-value%E2%91%A1%E2%91%A3",
             "tags": [
               "web-features:attr"
             ],
@@ -79,9 +80,11 @@
             }
           }
         },
-        "type-or-unit": {
+        "type_function": {
           "__compat": {
-            "description": "&lt;type-or-unit&gt;",
+            "description": "`type(<syntax>)` function",
+            "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/Reference/Values/attr#type",
+            "spec_url": "https://drafts.csswg.org/css-values-5/#funcdef-attr-type",
             "tags": [
               "web-features:attr"
             ],
@@ -116,7 +119,9 @@
           },
           "angle": {
             "__compat": {
-              "description": "&lt;angle&gt;",
+              "description": "`<angle>`",
+              "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/Reference/Values/angle",
+              "spec_url": "https://drafts.csswg.org/css-values-4/#angles",
               "tags": [
                 "web-features:attr"
               ],
@@ -152,7 +157,9 @@
           },
           "color": {
             "__compat": {
-              "description": "&lt;color&gt;",
+              "description": "`<color>`",
+              "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/Reference/Values/color_value",
+              "spec_url": "https://drafts.csswg.org/css-color/#color-syntax",
               "tags": [
                 "web-features:attr"
               ],
@@ -186,9 +193,125 @@
               }
             }
           },
+          "custom-ident": {
+            "__compat": {
+              "description": "`<custom-ident>`",
+              "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/Reference/Values/custom-ident",
+              "spec_url": "https://drafts.csswg.org/css-values/#custom-idents",
+              "tags": [
+                "web-features:attr"
+              ],
+              "support": {
+                "chrome": {
+                  "version_added": "133"
+                },
+                "chrome_android": "mirror",
+                "edge": "mirror",
+                "firefox": {
+                  "version_added": false,
+                  "impl_url": "https://bugzil.la/435426"
+                },
+                "firefox_android": "mirror",
+                "oculus": "mirror",
+                "opera": "mirror",
+                "opera_android": "mirror",
+                "safari": {
+                  "version_added": false,
+                  "impl_url": "https://webkit.org/b/26609"
+                },
+                "safari_ios": "mirror",
+                "samsunginternet_android": "mirror",
+                "webview_android": "mirror",
+                "webview_ios": "mirror"
+              },
+              "status": {
+                "experimental": true,
+                "standard_track": true,
+                "deprecated": false
+              }
+            }
+          },
+          "ident": {
+            "__compat": {
+              "description": "`<ident>`",
+              "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/Reference/Values/ident",
+              "spec_url": "https://drafts.csswg.org/css-values/#typedef-ident",
+              "tags": [
+                "web-features:attr"
+              ],
+              "support": {
+                "chrome": {
+                  "version_added": false
+                },
+                "chrome_android": "mirror",
+                "edge": "mirror",
+                "firefox": {
+                  "version_added": false,
+                  "impl_url": "https://bugzil.la/1871815"
+                },
+                "firefox_android": "mirror",
+                "oculus": "mirror",
+                "opera": "mirror",
+                "opera_android": "mirror",
+                "safari": {
+                  "version_added": false,
+                  "impl_url": "https://webkit.org/b/26609"
+                },
+                "safari_ios": "mirror",
+                "samsunginternet_android": "mirror",
+                "webview_android": "mirror",
+                "webview_ios": "mirror"
+              },
+              "status": {
+                "experimental": true,
+                "standard_track": true,
+                "deprecated": false
+              }
+            }
+          },
+          "image": {
+            "__compat": {
+              "description": "`<image>`",
+              "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/Reference/Values/image",
+              "spec_url": "https://drafts.csswg.org/css-images/#image-values",
+              "tags": [
+                "web-features:attr"
+              ],
+              "support": {
+                "chrome": {
+                  "version_added": false
+                },
+                "chrome_android": "mirror",
+                "edge": "mirror",
+                "firefox": {
+                  "version_added": false,
+                  "impl_url": "https://bugzil.la/435426"
+                },
+                "firefox_android": "mirror",
+                "oculus": "mirror",
+                "opera": "mirror",
+                "opera_android": "mirror",
+                "safari": {
+                  "version_added": false,
+                  "impl_url": "https://webkit.org/b/26609"
+                },
+                "safari_ios": "mirror",
+                "samsunginternet_android": "mirror",
+                "webview_android": "mirror",
+                "webview_ios": "mirror"
+              },
+              "status": {
+                "experimental": true,
+                "standard_track": true,
+                "deprecated": false
+              }
+            }
+          },
           "integer": {
             "__compat": {
-              "description": "&lt;integer&gt;",
+              "description": "`<integer>`",
+              "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/Reference/Values/integer",
+              "spec_url": "https://drafts.csswg.org/css-values/#integers",
               "tags": [
                 "web-features:attr"
               ],
@@ -224,7 +347,9 @@
           },
           "length": {
             "__compat": {
-              "description": "&lt;length&gt;",
+              "description": "`<length>`",
+              "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/Reference/Values/length",
+              "spec_url": "https://drafts.csswg.org/css-values/#lengths",
               "tags": [
                 "web-features:attr"
               ],
@@ -258,9 +383,49 @@
               }
             }
           },
+          "length-percentage": {
+            "__compat": {
+              "description": "`<length-percentage>`",
+              "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/Reference/Values/length-percentage",
+              "spec_url": "https://drafts.csswg.org/css-values/#mixed-percentages",
+              "tags": [
+                "web-features:attr"
+              ],
+              "support": {
+                "chrome": {
+                  "version_added": false
+                },
+                "chrome_android": "mirror",
+                "edge": "mirror",
+                "firefox": {
+                  "version_added": false,
+                  "impl_url": "https://bugzil.la/435426"
+                },
+                "firefox_android": "mirror",
+                "oculus": "mirror",
+                "opera": "mirror",
+                "opera_android": "mirror",
+                "safari": {
+                  "version_added": false,
+                  "impl_url": "https://webkit.org/b/26609"
+                },
+                "safari_ios": "mirror",
+                "samsunginternet_android": "mirror",
+                "webview_android": "mirror",
+                "webview_ios": "mirror"
+              },
+              "status": {
+                "experimental": true,
+                "standard_track": true,
+                "deprecated": false
+              }
+            }
+          },
           "number": {
             "__compat": {
-              "description": "&lt;number&gt;",
+              "description": "`<number>`",
+              "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/Reference/Values/number",
+              "spec_url": "https://drafts.csswg.org/css-values/#numbers",
               "tags": [
                 "web-features:attr"
               ],
@@ -296,7 +461,9 @@
           },
           "percentage": {
             "__compat": {
-              "description": "&lt;percentage&gt;",
+              "description": "`<percentage>`",
+              "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/Reference/Values/percentage",
+              "spec_url": "https://drafts.csswg.org/css-values/#percentages",
               "tags": [
                 "web-features:attr"
               ],
@@ -330,9 +497,87 @@
               }
             }
           },
+          "resolution": {
+            "__compat": {
+              "description": "`<resolution>`",
+              "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/Reference/Values/resolution",
+              "spec_url": "https://drafts.csswg.org/css-values/#resolution",
+              "tags": [
+                "web-features:attr"
+              ],
+              "support": {
+                "chrome": {
+                  "version_added": false
+                },
+                "chrome_android": "mirror",
+                "edge": "mirror",
+                "firefox": {
+                  "version_added": false,
+                  "impl_url": "https://bugzil.la/435426"
+                },
+                "firefox_android": "mirror",
+                "oculus": "mirror",
+                "opera": "mirror",
+                "opera_android": "mirror",
+                "safari": {
+                  "version_added": false,
+                  "impl_url": "https://webkit.org/b/26609"
+                },
+                "safari_ios": "mirror",
+                "samsunginternet_android": "mirror",
+                "webview_android": "mirror",
+                "webview_ios": "mirror"
+              },
+              "status": {
+                "experimental": true,
+                "standard_track": true,
+                "deprecated": false
+              }
+            }
+          },
+          "string": {
+            "__compat": {
+              "description": "`<string>`",
+              "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/Reference/Values/string",
+              "spec_url": "https://drafts.csswg.org/css-values/#strings",
+              "tags": [
+                "web-features:attr"
+              ],
+              "support": {
+                "chrome": {
+                  "version_added": "133"
+                },
+                "chrome_android": "mirror",
+                "edge": "mirror",
+                "firefox": {
+                  "version_added": false,
+                  "impl_url": "https://bugzil.la/435426"
+                },
+                "firefox_android": "mirror",
+                "oculus": "mirror",
+                "opera": "mirror",
+                "opera_android": "mirror",
+                "safari": {
+                  "version_added": false,
+                  "impl_url": "https://webkit.org/b/26609"
+                },
+                "safari_ios": "mirror",
+                "samsunginternet_android": "mirror",
+                "webview_android": "mirror",
+                "webview_ios": "mirror"
+              },
+              "status": {
+                "experimental": true,
+                "standard_track": true,
+                "deprecated": false
+              }
+            }
+          },
           "time": {
             "__compat": {
-              "description": "&lt;time&gt;",
+              "description": "`<time>`",
+              "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/Reference/Values/time",
+              "spec_url": "https://drafts.csswg.org/css-values/#time",
               "tags": [
                 "web-features:attr"
               ],
@@ -365,6 +610,82 @@
                 "deprecated": false
               }
             }
+          },
+          "transform-function": {
+            "__compat": {
+              "description": "`<transform-function>`",
+              "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/Reference/Values/transform-function",
+              "spec_url": "https://drafts.csswg.org/css-transforms-2/#transform-functions",
+              "tags": [
+                "web-features:attr"
+              ],
+              "support": {
+                "chrome": {
+                  "version_added": false
+                },
+                "chrome_android": "mirror",
+                "edge": "mirror",
+                "firefox": {
+                  "version_added": false,
+                  "impl_url": "https://bugzil.la/435426"
+                },
+                "firefox_android": "mirror",
+                "oculus": "mirror",
+                "opera": "mirror",
+                "opera_android": "mirror",
+                "safari": {
+                  "version_added": false,
+                  "impl_url": "https://webkit.org/b/26609"
+                },
+                "safari_ios": "mirror",
+                "samsunginternet_android": "mirror",
+                "webview_android": "mirror",
+                "webview_ios": "mirror"
+              },
+              "status": {
+                "experimental": true,
+                "standard_track": true,
+                "deprecated": false
+              }
+            }
+          },
+          "url": {
+            "__compat": {
+              "description": "`<url>`",
+              "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/Reference/Values/url_value",
+              "spec_url": "https://drafts.csswg.org/css-values/#url-value",
+              "tags": [
+                "web-features:attr"
+              ],
+              "support": {
+                "chrome": {
+                  "version_added": "133"
+                },
+                "chrome_android": "mirror",
+                "edge": "mirror",
+                "firefox": {
+                  "version_added": false,
+                  "impl_url": "https://bugzil.la/1448252"
+                },
+                "firefox_android": "mirror",
+                "oculus": "mirror",
+                "opera": "mirror",
+                "opera_android": "mirror",
+                "safari": {
+                  "version_added": false,
+                  "impl_url": "https://webkit.org/b/26609"
+                },
+                "safari_ios": "mirror",
+                "samsunginternet_android": "mirror",
+                "webview_android": "mirror",
+                "webview_ios": "mirror"
+              },
+              "status": {
+                "experimental": true,
+                "standard_track": true,
+                "deprecated": false
+              }
+            }
           }
         }
       }