{ "$schema": "http://json-schema.org/draft-04/schema#"
, "type": "object"
, "properties" :
  { "rel" :
    { "type" : "array"
    , "items" :
      [ { "type" : "string"
        , "pattern" : "up"
        }
      ]
    }
  , "href" :
    { "type" : "string"
    }
  }
}