diff --git a/css/at-rules/keyframes.json b/css/at-rules/keyframes.json
index 24c0c1c0040934..8a43e6fa855580 100644
--- a/css/at-rules/keyframes.json
+++ b/css/at-rules/keyframes.json
@@ -166,10 +166,10 @@
             "description": "Ignore <code>!important</code> declarations",
             "support": {
               "chrome": {
-                "version_added": null
+                "version_added": "45"
               },
               "chrome_android": {
-                "version_added": null
+                "version_added": "45"
               },
               "edge": {
                 "version_added": null
@@ -187,10 +187,10 @@
                 "version_added": false
               },
               "opera": {
-                "version_added": null
+                "version_added": "32"
               },
               "opera_android": {
-                "version_added": null
+                "version_added": "32"
               },
               "safari": {
                 "version_added": null
@@ -199,10 +199,10 @@
                 "version_added": null
               },
               "samsunginternet_android": {
-                "version_added": null
+                "version_added": true
               },
               "webview_android": {
-                "version_added": null
+                "version_added": "45"
               }
             },
             "status": {
diff --git a/css/at-rules/media.json b/css/at-rules/media.json
index 61ed9404eec9de..96a2069ede982b 100644
--- a/css/at-rules/media.json
+++ b/css/at-rules/media.json
@@ -367,10 +367,10 @@
             "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/@media/color-index",
             "support": {
               "chrome": {
-                "version_added": true
+                "version_added": false
               },
               "chrome_android": {
-                "version_added": true
+                "version_added": false
               },
               "edge": {
                 "version_added": null
@@ -388,10 +388,10 @@
                 "version_added": false
               },
               "opera": {
-                "version_added": null
+                "version_added": false
               },
               "opera_android": {
-                "version_added": null
+                "version_added": false
               },
               "safari": {
                 "version_added": null
@@ -400,10 +400,10 @@
                 "version_added": null
               },
               "samsunginternet_android": {
-                "version_added": null
+                "version_added": false
               },
               "webview_android": {
-                "version_added": true
+                "version_added": false
               }
             },
             "status": {
@@ -1720,10 +1720,12 @@
             "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/@media/-webkit-animation",
             "support": {
               "chrome": {
-                "version_added": true
+                "version_added": true,
+                "version_removed": "36"
               },
               "chrome_android": {
-                "version_added": true
+                "version_added": true,
+                "version_removed": "36"
               },
               "edge": {
                 "version_added": null
@@ -1741,10 +1743,12 @@
                 "version_added": false
               },
               "opera": {
-                "version_added": null
+                "version_added": true,
+                "version_removed": "23"
               },
               "opera_android": {
-                "version_added": null
+                "version_added": true,
+                "version_removed": "24"
               },
               "safari": {
                 "version_added": null
@@ -1753,10 +1757,12 @@
                 "version_added": null
               },
               "samsunginternet_android": {
-                "version_added": null
+                "version_added": true,
+                "version_removed": true
               },
               "webview_android": {
-                "version_added": true
+                "version_added": true,
+                "version_removed": "37"
               }
             },
             "status": {
diff --git a/css/at-rules/page.json b/css/at-rules/page.json
index fe7f37882a5d4f..e64162c95af67c 100644
--- a/css/at-rules/page.json
+++ b/css/at-rules/page.json
@@ -58,10 +58,10 @@
             "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/@page/bleed",
             "support": {
               "chrome": {
-                "version_added": null
+                "version_added": false
               },
               "chrome_android": {
-                "version_added": null
+                "version_added": false
               },
               "edge": {
                 "version_added": null
@@ -79,10 +79,10 @@
                 "version_added": false
               },
               "opera": {
-                "version_added": null
+                "version_added": false
               },
               "opera_android": {
-                "version_added": null
+                "version_added": false
               },
               "safari": {
                 "version_added": false
@@ -91,10 +91,10 @@
                 "version_added": null
               },
               "samsunginternet_android": {
-                "version_added": null
+                "version_added": false
               },
               "webview_android": {
-                "version_added": null
+                "version_added": false
               }
             },
             "status": {
@@ -110,10 +110,10 @@
             "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/@page/marks",
             "support": {
               "chrome": {
-                "version_added": null
+                "version_added": false
               },
               "chrome_android": {
-                "version_added": null
+                "version_added": false
               },
               "edge": {
                 "version_added": null
@@ -131,10 +131,10 @@
                 "version_added": false
               },
               "opera": {
-                "version_added": null
+                "version_added": false
               },
               "opera_android": {
-                "version_added": null
+                "version_added": false
               },
               "safari": {
                 "version_added": false
@@ -143,10 +143,10 @@
                 "version_added": null
               },
               "samsunginternet_android": {
-                "version_added": null
+                "version_added": false
               },
               "webview_android": {
-                "version_added": null
+                "version_added": false
               }
             },
             "status": {
diff --git a/css/at-rules/viewport.json b/css/at-rules/viewport.json
index 5d5b4ff3f7ca4f..184df8d1352b5f 100644
--- a/css/at-rules/viewport.json
+++ b/css/at-rules/viewport.json
@@ -679,10 +679,10 @@
             "description": "<code>viewport-fit</code> descriptor",
             "support": {
               "chrome": {
-                "version_added": null
+                "version_added": false
               },
               "edge": {
-                "version_added": null
+                "version_added": false
               },
               "firefox": {
                 "version_added": false
@@ -694,7 +694,7 @@
                 "version_added": false
               },
               "opera": {
-                "version_added": null
+                "version_added": false
               },
               "safari": {
                 "version_added": false