acre (based on US survey foot)

{
  "id": "NISTu317",
  "unitsml_id": "u:us_acre",
  "name": "acre (based on US survey foot)",
  "names": [
    {
      "value": "acre (based on US survey foot)",
      "lang": "en"
    },
    {
      "value": "acre",
      "lang": "en"
    }
  ],
  "symbols": {
    "unicode": "ac",
    "ascii": "ac",
    "html": "ac",
    "latex": "\\ensuremath{\\mathrm{ac}}",
    "id": "ac",
    "mathml": "<mi mathvariant='normal'>ac</mi>"
  },
  "identifiers": [
    {
      "type": "nist",
      "id": "NISTu317"
    },
    {
      "type": "unitsml",
      "id": "u:us_acre"
    }
  ],
  "references": [
    {
      "type": "informative",
      "authority": "ucum",
      "uri": "ucum:unit:us-lengths:code:[acr_us]"
    },
    {
      "type": "informative",
      "authority": "qudt",
      "uri": "http://qudt.org/vocab/unit/AC"
    }
  ],
  "short": "us_acre",
  "root": true,
  "composite": false,
  "quantities": [
    {
      "id": "NISTq8",
      "name": "area",
      "type": "derived"
    }
  ],
  "dimension": {
    "id": "NISTd8",
    "name": "area",
    "expression": "L2",
    "components": [
      {
        "key": "length",
        "symbol": "L",
        "power": 2
      }
    ],
    "dimensionless": false
  },
  "scale": {
    "id": "continuous_ratio",
    "name": "continuous ratio scale"
  },
  "systems": [
    {
      "id": "non-SI_not_acceptable",
      "name": "non-SI and not acceptable",
      "short": "nonsi-unacceptable",
      "acceptable": false
    }
  ],
  "root_units": null
}