{
  "-moz-meter-bar": {
    "alias-for": "slider-fill"
  },
  "-moz-placeholder": {
    "alias-for": "placeholder"
  },
  "-moz-progress-bar": {
    "alias-for": "slider-fill"
  },
  "-moz-range-progress": {
    "alias-for": "slider-fill"
  },
  "-moz-range-track": {
    "alias-for": "slider-track"
  },
  "-moz-range-thumb": {
    "alias-for": "slider-thumb"
  },
  "-webkit-input-placeholder": {
    "alias-for": "placeholder"
  },
  "-webkit-meter-bar": {
    "alias-for": "slider-track"
  },
  "-webkit-progress-bar": {
    "alias-for": "slider-track"
  },
  "-webkit-progress-value": {
    "alias-for": "slider-fill"
  },
  "-webkit-slider-runnable-track": {
    "alias-for": "slider-track"
  },
  "-webkit-slider-thumb": {
    "alias-for": "slider-thumb"
  },
  "after": {
    "spec": "https://drafts.csswg.org/css-pseudo-4/#selectordef-after",
    "is-tree-abiding": true
  },
  "backdrop": {
    "spec": "https://drafts.csswg.org/css-position-4/#selectordef-backdrop"
  },
  "before": {
    "spec": "https://drafts.csswg.org/css-pseudo-4/#selectordef-before",
    "is-tree-abiding": true
  },
  "details-content": {
    "spec": "https://drafts.csswg.org/css-pseudo-4/#selectordef-details-content",
    "is-element-backed": true
  },
  "file-selector-button": {
    "spec": "https://drafts.csswg.org/css-pseudo-4/#selectordef-file-selector-button",
    "is-element-backed": true
  },
  "first-letter": {
    "spec": "https://drafts.csswg.org/css-pseudo-4/#selectordef-first-letter",
    "property-whitelist": [
      "#font-properties",
      "color",
      "opacity",
      "#background-properties",
      "#inline-typesetting-properties",
      "#text-decoration-properties",
      "#inline-layout-properties",
      "#margin-properties",
      "#padding-properties",
      "#border-properties",
      "box-shadow",
      "#custom-properties"
    ]
  },
  "first-line": {
    "spec": "https://drafts.csswg.org/css-pseudo-4/#selectordef-first-line",
    "property-whitelist": [
      "#font-properties",
      "color",
      "opacity",
      "#background-properties",
      "#inline-typesetting-properties",
      "#text-decoration-properties",
      "#custom-properties",
      "FIXME: ruby-position",
      "#inline-layout-properties"
    ]
  },
  "marker": {
    "spec": "https://drafts.csswg.org/css-pseudo-4/#selectordef-marker",
    "is-tree-abiding": true
  },
  "part": {
    "spec": "https://drafts.csswg.org/css-shadow-1/#selectordef-part",
    "type": "function",
    "function-syntax": "<ident>+",
    "is-element-backed": true
  },
  "placeholder": {
    "spec": "https://drafts.csswg.org/css-pseudo-4/#selectordef-placeholder",
    "is-tree-abiding": true,
    "property-whitelist": [
      "#font-properties",
      "color",
      "opacity",
      "#background-properties",
      "#inline-typesetting-properties",
      "#text-decoration-properties",
      "#custom-properties",
      "FIXME: ruby-position"
    ]
  },
  "selection": {
    "spec": "https://drafts.csswg.org/css-pseudo-4/#selectordef-selection",
    "property-whitelist": [
      "color",
      "background-color",
      "#text-decoration-properties",
      "text-shadow",
      "FIXME: stroke-color",
      "FIXME: fill-color",
      "stroke-width",
      "#custom-properties"
    ]
  },
  "slider-fill": {
    "spec": "https://drafts.csswg.org/css-forms-1/#selectordef-slider-fill"
  },
  "slider-thumb": {
    "spec": "https://drafts.csswg.org/css-forms-1/#selectordef-slider-thumb"
  },
  "slider-track": {
    "spec": "https://drafts.csswg.org/css-forms-1/#selectordef-slider-track"
  },
  "slotted": {
    "spec": "https://drafts.csswg.org/css-shadow-1/#slotted-pseudo",
    "type": "function",
    "function-syntax": "<compound-selector>",
    "is-element-backed": true
  },
  "view-transition": {
    "spec": "https://drafts.csswg.org/css-view-transitions-1/#selectordef-view-transition",
    "is-pseudo-root": true
  },
  "view-transition-group": {
    "spec": "https://drafts.csswg.org/css-view-transitions-1/#selectordef-view-transition-group",
    "type": "function",
    "function-syntax": "<pt-name-selector>"
  },
  "view-transition-image-pair": {
    "spec": "https://drafts.csswg.org/css-view-transitions-1/#selectordef-view-transition-image-pair",
    "type": "function",
    "function-syntax": "<pt-name-selector>"
  },
  "view-transition-new": {
    "spec": "https://drafts.csswg.org/css-view-transitions-1/#selectordef-view-transition-new",
    "type": "function",
    "function-syntax": "<pt-name-selector>"
  },
  "view-transition-old": {
    "spec": "https://drafts.csswg.org/css-view-transitions-1/#selectordef-view-transition-old",
    "type": "function",
    "function-syntax": "<pt-name-selector>"
  }
}