{
  "prefbar:info": {
    "formatversion": 3
  },
  "prefbar:menu:enabled": {
    "items": [
      "prefbar:button:tabmetaredirect"
    ]
  },
  "prefbar:button:tabmetaredirect": {
    "type": "extcheck",
    "label": "MetaRedirect (Tab)",
    "setfunction": "prefbarGetDocShell().allowMetaRedirects = value;",
    "getfunction": "value = prefbarGetDocShell().allowMetaRedirects;",
    "browserbtnupdatefor": "tab"
  }
}