acre-foot (based on US survey foot)

{
  "id": "NISTu57",
  "unitsml_id": "u:us_survey_acre_foot",
  "name": "acre-foot (based on US survey foot)",
  "names": [
    {
      "value": "acre-foot (based on US survey foot)",
      "lang": "en"
    },
    {
      "value": "acre-foot",
      "lang": "en"
    }
  ],
  "symbols": {
    "unicode": "ac·ft",
    "ascii": "ac*ft",
    "html": "ac · ft",
    "latex": "\\ensuremath{\\mathrm{ac\\cdot ft}}",
    "id": "ac*ft",
    "mathml": "<mrow><mi mathvariant='normal'>ac</mi><mo>&#183;</mo><mi mathvariant='normal'>ft</mi></mrow>"
  },
  "identifiers": [
    {
      "type": "nist",
      "id": "NISTu57"
    },
    {
      "type": "unitsml",
      "id": "u:us_survey_acre_foot"
    }
  ],
  "references": [
    {
      "type": "informative",
      "authority": "qudt",
      "uri": "http://qudt.org/vocab/unit/AC-FT"
    }
  ],
  "short": "us_survey_acre_foot",
  "root": false,
  "composite": true,
  "quantities": [
    {
      "id": "NISTq10",
      "name": "volume",
      "type": "derived"
    }
  ],
  "dimension": {
    "id": "NISTd10",
    "name": "volume",
    "expression": "L3",
    "components": [
      {
        "key": "length",
        "symbol": "L",
        "power": 3
      }
    ],
    "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": [
    {
      "power": 1,
      "unit": {
        "id": "NISTu317",
        "name": "acre (based on US survey foot)",
        "symbol": "ac"
      },
      "prefix": null
    },
    {
      "power": 1,
      "unit": {
        "id": "NISTu78",
        "name": "foot",
        "symbol": "′"
      },
      "prefix": null
    }
  ]
}