"Ь" meaning in Russe

{
  "categories": [
    {
      "kind": "other",
      "name": "Lemmes en russe",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Lettres en russe",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Russe",
      "orig": "russe",
      "parents": [],
      "source": "w"
    }
  ],
  "lang": "Russe",
  "lang_code": "ru",
  "pos": "character",
  "pos_title": "Lettre",
  "senses": [
    {
      "glosses": [
        "Signe mou (ou yat’ ять, ou ě) : trentième lettre et dixième voyelle de l’alphabet (majuscule)."
      ],
      "id": "fr-Ь-ru-character-WstZbPEp"
    },
    {
      "glosses": [
        "Transcription : « IÉ »."
      ],
      "id": "fr-Ь-ru-character-iQmhuB6V"
    }
  ],
  "sounds": [
    {
      "ipa": "\\ʲɛ\\"
    }
  ],
  "tags": [
    "letter"
  ],
  "word": "Ь"
}

{
  "categories": [
    "Lemmes en russe",
    "Lettres en russe",
    "russe"
  ],
  "lang": "Russe",
  "lang_code": "ru",
  "pos": "character",
  "pos_title": "Lettre",
  "senses": [
    {
      "glosses": [
        "Signe mou (ou yat’ ять, ou ě) : trentième lettre et dixième voyelle de l’alphabet (majuscule)."
      ]
    },
    {
      "glosses": [
        "Transcription : « IÉ »."
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "\\ʲɛ\\"
    }
  ],
  "tags": [
    "letter"
  ],
  "word": "Ь"
}