"??" meaning in Conventions internationales

{
  "categories": [
    {
      "kind": "other",
      "name": "Palindromes en conventions internationales",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Palindromes 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"
    }
  ],
  "lang": "Conventions internationales",
  "lang_code": "conv",
  "pos": "symbol",
  "pos_title": "Symbole 1",
  "senses": [
    {
      "glosses": [
        "Erreur grossière."
      ],
      "id": "fr-??-conv-symbol-MOHVPpTh",
      "raw_tags": [
        "Aux échecs"
      ]
    }
  ],
  "word": "??"
}

{
  "categories": [
    {
      "kind": "other",
      "name": "Palindromes en conventions internationales",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Palindromes 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"
    }
  ],
  "lang": "Conventions internationales",
  "lang_code": "conv",
  "pos": "symbol",
  "pos_title": "Symbole 2",
  "related": [
    {
      "word": "*"
    }
  ],
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Lexique en conventions internationales de la linguistique",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "Acceptabilité très douteuse."
      ],
      "id": "fr-??-conv-symbol-6QrQmtvj",
      "topics": [
        "linguistic"
      ]
    }
  ],
  "word": "??"
}

{
  "categories": [
    {
      "kind": "other",
      "name": "Symboles en conventions internationales",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Conventions internationales",
      "orig": "conventions internationales",
      "parents": [],
      "source": "w"
    }
  ],
  "lang": "Conventions internationales",
  "lang_code": "conv",
  "pos": "symbol",
  "pos_title": "Symbole 3",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Signes de ponctuation en conventions internationales",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Wiktionnaire:Exemples manquants en conventions internationales",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "Utilisé à la fin des phrases comme une version accentuée de ?, pour donner plus de poids et d’importance aux questions, comme si elles exigeaient une réponse."
      ],
      "id": "fr-??-conv-symbol-4QPmgSbt",
      "topics": [
        "typography"
      ]
    }
  ],
  "word": "??"
}

{
  "categories": [
    "Palindromes en conventions internationales",
    "Palindromes en français",
    "Symboles en conventions internationales",
    "conventions internationales"
  ],
  "lang": "Conventions internationales",
  "lang_code": "conv",
  "pos": "symbol",
  "pos_title": "Symbole 1",
  "senses": [
    {
      "glosses": [
        "Erreur grossière."
      ],
      "raw_tags": [
        "Aux échecs"
      ]
    }
  ],
  "word": "??"
}

{
  "categories": [
    "Palindromes en conventions internationales",
    "Palindromes en français",
    "Symboles en conventions internationales",
    "conventions internationales"
  ],
  "lang": "Conventions internationales",
  "lang_code": "conv",
  "pos": "symbol",
  "pos_title": "Symbole 2",
  "related": [
    {
      "word": "*"
    }
  ],
  "senses": [
    {
      "categories": [
        "Lexique en conventions internationales de la linguistique"
      ],
      "glosses": [
        "Acceptabilité très douteuse."
      ],
      "topics": [
        "linguistic"
      ]
    }
  ],
  "word": "??"
}

{
  "categories": [
    "Symboles en conventions internationales",
    "conventions internationales"
  ],
  "lang": "Conventions internationales",
  "lang_code": "conv",
  "pos": "symbol",
  "pos_title": "Symbole 3",
  "senses": [
    {
      "categories": [
        "Signes de ponctuation en conventions internationales",
        "Wiktionnaire:Exemples manquants en conventions internationales"
      ],
      "glosses": [
        "Utilisé à la fin des phrases comme une version accentuée de ?, pour donner plus de poids et d’importance aux questions, comme si elles exigeaient une réponse."
      ],
      "topics": [
        "typography"
      ]
    }
  ],
  "word": "??"
}