"ua" meaning in Conventions internationales

{
  "categories": [
    {
      "kind": "other",
      "name": "Dates manquantes en conventions internationales",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Mots en conventions internationales issus d’un mot en français",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Symboles en conventions internationales",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Conventions internationales",
      "orig": "conventions internationales",
      "parents": [],
      "source": "w"
    }
  ],
  "etymology_texts": [
    "(Date à préciser) Du français unité astronomique."
  ],
  "lang": "Conventions internationales",
  "lang_code": "conv",
  "pos": "symbol",
  "pos_title": "Symbole",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Lexique en conventions internationales de l’astronomie",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "Unité astronomique."
      ],
      "id": "fr-ua-conv-symbol-5Y8FIW5v",
      "note": "Presque seulement utilisé dans la francophonie",
      "topics": [
        "astronomy"
      ]
    }
  ],
  "synonyms": [
    {
      "sense": "depuis 2012",
      "word": "au"
    },
    {
      "sense": "anglophonie",
      "word": "AU"
    }
  ],
  "word": "ua"
}

{
  "categories": [
    "Dates manquantes en conventions internationales",
    "Mots en conventions internationales issus d’un mot en français",
    "Symboles en conventions internationales",
    "conventions internationales"
  ],
  "etymology_texts": [
    "(Date à préciser) Du français unité astronomique."
  ],
  "lang": "Conventions internationales",
  "lang_code": "conv",
  "pos": "symbol",
  "pos_title": "Symbole",
  "senses": [
    {
      "categories": [
        "Lexique en conventions internationales de l’astronomie"
      ],
      "glosses": [
        "Unité astronomique."
      ],
      "note": "Presque seulement utilisé dans la francophonie",
      "topics": [
        "astronomy"
      ]
    }
  ],
  "synonyms": [
    {
      "sense": "depuis 2012",
      "word": "au"
    },
    {
      "sense": "anglophonie",
      "word": "AU"
    }
  ],
  "word": "ua"
}