diff --git a/css/properties/-webkit-border-before.json b/css/properties/-webkit-border-before.json
new file mode 100644
index 0000000000000..fb030dd3ff19b
--- /dev/null
+++ b/css/properties/-webkit-border-before.json
@@ -0,0 +1,57 @@
+{
+  "css": {
+    "properties": {
+      "-webkit-border-before": {
+        "__compat": {
+          "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/-webkit-border-before",
+          "support": {
+            "chrome": {
+              "version_added": true
+            },
+            "chrome_android": {
+              "version_added": true
+            },
+            "edge": {
+              "version_added": null
+            },
+            "edge_mobile": {
+              "version_added": null
+            },
+            "firefox": {
+              "version_added": false
+            },
+            "firefox_android": {
+              "version_added": false
+            },
+            "ie": {
+              "version_added": false
+            },
+            "opera": {
+              "version_added": true
+            },
+            "opera_android": {
+              "version_added": null
+            },
+            "safari": {
+              "version_added": null
+            },
+            "safari_ios": {
+              "version_added": null
+            },
+            "samsunginternet_android": {
+              "version_added": null
+            },
+            "webview_android": {
+              "version_added": true
+            }
+          },
+          "status": {
+            "experimental": false,
+            "standard_track": false,
+            "deprecated": false
+          }
+        }
+      }
+    }
+  }
+}
diff --git a/css/properties/-webkit-box-reflect.json b/css/properties/-webkit-box-reflect.json
new file mode 100644
index 0000000000000..ef5f71a4c263a
--- /dev/null
+++ b/css/properties/-webkit-box-reflect.json
@@ -0,0 +1,57 @@
+{
+  "css": {
+    "properties": {
+      "-webkit-box-reflect": {
+        "__compat": {
+          "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/-webkit-box-reflect",
+          "support": {
+            "chrome": {
+              "version_added": "4"
+            },
+            "chrome_android": {
+              "version_added": true
+            },
+            "edge": {
+              "version_added": null
+            },
+            "edge_mobile": {
+              "version_added": null
+            },
+            "firefox": {
+              "version_added": false
+            },
+            "firefox_android": {
+              "version_added": false
+            },
+            "ie": {
+              "version_added": false
+            },
+            "opera": {
+              "version_added": "15"
+            },
+            "opera_android": {
+              "version_added": "22"
+            },
+            "safari": {
+              "version_added": "4"
+            },
+            "safari_ios": {
+              "version_added": "3.2"
+            },
+            "samsunginternet_android": {
+              "version_added": null
+            },
+            "webview_android": {
+              "version_added": "2.2"
+            }
+          },
+          "status": {
+            "experimental": false,
+            "standard_track": false,
+            "deprecated": false
+          }
+        }
+      }
+    }
+  }
+}
diff --git a/css/properties/-webkit-mask-composite.json b/css/properties/-webkit-mask-composite.json
new file mode 100644
index 0000000000000..62f09e0c6f365
--- /dev/null
+++ b/css/properties/-webkit-mask-composite.json
@@ -0,0 +1,57 @@
+{
+  "css": {
+    "properties": {
+      "-webkit-mask-composite": {
+        "__compat": {
+          "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/-webkit-mask-composite",
+          "support": {
+            "chrome": {
+              "version_added": "1"
+            },
+            "chrome_android": {
+              "version_added": true
+            },
+            "edge": {
+              "version_added": null
+            },
+            "edge_mobile": {
+              "version_added": null
+            },
+            "firefox": {
+              "version_added": false
+            },
+            "firefox_android": {
+              "version_added": false
+            },
+            "ie": {
+              "version_added": false
+            },
+            "opera": {
+              "version_added": false
+            },
+            "opera_android": {
+              "version_added": false
+            },
+            "safari": {
+              "version_added": "4"
+            },
+            "safari_ios": {
+              "version_added": "3.2"
+            },
+            "samsunginternet_android": {
+              "version_added": null
+            },
+            "webview_android": {
+              "version_added": "2.2"
+            }
+          },
+          "status": {
+            "experimental": false,
+            "standard_track": false,
+            "deprecated": false
+          }
+        }
+      }
+    }
+  }
+}
diff --git a/css/selectors/-moz-color-swatch.json b/css/selectors/-moz-color-swatch.json
new file mode 100644
index 0000000000000..12483dde11672
--- /dev/null
+++ b/css/selectors/-moz-color-swatch.json
@@ -0,0 +1,58 @@
+{
+  "css": {
+    "selectors": {
+      "-moz-color-swatch": {
+        "__compat": {
+          "description": "<code>::-moz-color-swatch</code>",
+          "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/::-moz-color-swatch",
+          "support": {
+            "chrome": {
+              "version_added": false
+            },
+            "chrome_android": {
+              "version_added": false
+            },
+            "edge": {
+              "version_added": null
+            },
+            "edge_mobile": {
+              "version_added": null
+            },
+            "firefox": {
+              "version_added": true
+            },
+            "firefox_android": {
+              "version_added": true
+            },
+            "ie": {
+              "version_added": false
+            },
+            "opera": {
+              "version_added": false
+            },
+            "opera_android": {
+              "version_added": false
+            },
+            "safari": {
+              "version_added": false
+            },
+            "safari_ios": {
+              "version_added": false
+            },
+            "samsunginternet_android": {
+              "version_added": false
+            },
+            "webview_android": {
+              "version_added": false
+            }
+          },
+          "status": {
+            "experimental": false,
+            "standard_track": false,
+            "deprecated": false
+          }
+        }
+      }
+    }
+  }
+}
diff --git a/css/selectors/-webkit-autofill.json b/css/selectors/-webkit-autofill.json
new file mode 100644
index 0000000000000..25eaa1ad0d172
--- /dev/null
+++ b/css/selectors/-webkit-autofill.json
@@ -0,0 +1,58 @@
+{
+  "css": {
+    "selectors": {
+      "-webkit-autofill": {
+        "__compat": {
+          "description": "<code>:-webkit-autofill</code>",
+          "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/:-webkit-autofill",
+          "support": {
+            "chrome": {
+              "version_added": true
+            },
+            "chrome_android": {
+              "version_added": true
+            },
+            "edge": {
+              "version_added": null
+            },
+            "edge_mobile": {
+              "version_added": null
+            },
+            "firefox": {
+              "version_added": false
+            },
+            "firefox_android": {
+              "version_added": null
+            },
+            "ie": {
+              "version_added": null
+            },
+            "opera": {
+              "version_added": null
+            },
+            "opera_android": {
+              "version_added": null
+            },
+            "safari": {
+              "version_added": true
+            },
+            "safari_ios": {
+              "version_added": null
+            },
+            "samsunginternet_android": {
+              "version_added": null
+            },
+            "webview_android": {
+              "version_added": true
+            }
+          },
+          "status": {
+            "experimental": false,
+            "standard_track": false,
+            "deprecated": false
+          }
+        }
+      }
+    }
+  }
+}
diff --git a/css/selectors/-webkit-file-upload-button.json b/css/selectors/-webkit-file-upload-button.json
new file mode 100644
index 0000000000000..c36d3a7fa59b3
--- /dev/null
+++ b/css/selectors/-webkit-file-upload-button.json
@@ -0,0 +1,55 @@
+{
+  "css": {
+    "selectors": {
+      "-webkit-file-upload-button": {
+        "__compat": {
+          "description": "<code>::-webkit-file-upload-button</code>",
+          "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/::-webkit-file-upload-button",
+          "support": {
+            "chrome": {
+              "version_added": true
+            },
+            "chrome_android": {
+              "version_added": true
+            },
+            "edge": {
+              "version_added": false
+            },
+            "edge_mobile": {
+              "version_added": false
+            },
+            "firefox": {
+              "version_added": false
+            },
+            "firefox_android": {
+              "version_added": false
+            },
+            "ie": {
+              "version_added": false
+            },
+            "opera": {
+              "version_added": true
+            },
+            "opera_android": {
+              "version_added": true
+            },
+            "safari": {
+              "version_added": true
+            },
+            "safari_ios": {
+              "version_added": true
+            },
+            "webview_android": {
+              "version_added": true
+            }
+          },
+          "status": {
+            "experimental": false,
+            "standard_track": false,
+            "deprecated": false
+          }
+        }
+      }
+    }
+  }
+}
diff --git a/css/selectors/-webkit-inner-spin-button.json b/css/selectors/-webkit-inner-spin-button.json
new file mode 100644
index 0000000000000..6b2096258894a
--- /dev/null
+++ b/css/selectors/-webkit-inner-spin-button.json
@@ -0,0 +1,58 @@
+{
+  "css": {
+    "selectors": {
+      "-webkit-inner-spin-button": {
+        "__compat": {
+          "description": "<code>::-webkit-inner-spin-button</code>",
+          "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/::-webkit-inner-spin-button",
+          "support": {
+            "chrome": {
+              "version_added": true
+            },
+            "chrome_android": {
+              "version_added": true
+            },
+            "edge": {
+              "version_added": null
+            },
+            "edge_mobile": {
+              "version_added": null
+            },
+            "firefox": {
+              "version_added": false
+            },
+            "firefox_android": {
+              "version_added": null
+            },
+            "ie": {
+              "version_added": null
+            },
+            "opera": {
+              "version_added": true
+            },
+            "opera_android": {
+              "version_added": null
+            },
+            "safari": {
+              "version_added": true
+            },
+            "safari_ios": {
+              "version_added": null
+            },
+            "samsunginternet_android": {
+              "version_added": null
+            },
+            "webview_android": {
+              "version_added": true
+            }
+          },
+          "status": {
+            "experimental": false,
+            "standard_track": false,
+            "deprecated": false
+          }
+        }
+      }
+    }
+  }
+}
diff --git a/css/selectors/-webkit-outer-spin-button.json b/css/selectors/-webkit-outer-spin-button.json
new file mode 100644
index 0000000000000..a0c405dbfe2e8
--- /dev/null
+++ b/css/selectors/-webkit-outer-spin-button.json
@@ -0,0 +1,58 @@
+{
+  "css": {
+    "selectors": {
+      "-webkit-outer-spin-button": {
+        "__compat": {
+          "description": "<code>::-webkit-outer-spin-button</code>",
+          "mdn_url": "https://developer.mozilla.org/docs/Web/CSS/::-webkit-outer-spin-button",
+          "support": {
+            "chrome": {
+              "version_added": true
+            },
+            "chrome_android": {
+              "version_added": true
+            },
+            "edge": {
+              "version_added": null
+            },
+            "edge_mobile": {
+              "version_added": null
+            },
+            "firefox": {
+              "version_added": false
+            },
+            "firefox_android": {
+              "version_added": null
+            },
+            "ie": {
+              "version_added": null
+            },
+            "opera": {
+              "version_added": true
+            },
+            "opera_android": {
+              "version_added": null
+            },
+            "safari": {
+              "version_added": true
+            },
+            "safari_ios": {
+              "version_added": null
+            },
+            "samsunginternet_android": {
+              "version_added": null
+            },
+            "webview_android": {
+              "version_added": true
+            }
+          },
+          "status": {
+            "experimental": false,
+            "standard_track": false,
+            "deprecated": false
+          }
+        }
+      }
+    }
+  }
+}