"т.н." meaning in Russian

{
  "forms": [
    {
      "form": "t.n.",
      "tags": [
        "alternative"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "indecl": "1"
      },
      "expansion": "т.н. • (t.n.) (indeclinable)",
      "name": "ru-adj"
    }
  ],
  "lang": "Russian",
  "lang_code": "ru",
  "pos": "adj",
  "senses": [
    {
      "alt_of": [
        {
          "extra": "tak nazyvájemyj, “so-called”",
          "word": "так называ́емый"
        }
      ],
      "categories": [
        {
          "kind": "other",
          "name": "Russian entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "initialism of так называ́емый (tak nazyvájemyj, “so-called”)"
      ],
      "id": "en-т.н.-ru-adj-EKsprkKC",
      "links": [
        [
          "так называ́емый",
          "так называемый#Russian"
        ],
        [
          "so-called",
          "so-called"
        ]
      ],
      "synonyms": [
        {
          "roman": "t. naz.",
          "word": "т. наз."
        }
      ],
      "tags": [
        "abbreviation",
        "alt-of",
        "indeclinable",
        "initialism"
      ]
    }
  ],
  "word": "т.н."
}

{
  "forms": [
    {
      "form": "t.n.",
      "tags": [
        "alternative"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "indecl": "1"
      },
      "expansion": "т.н. • (t.n.) (indeclinable)",
      "name": "ru-adj"
    }
  ],
  "lang": "Russian",
  "lang_code": "ru",
  "pos": "adj",
  "senses": [
    {
      "alt_of": [
        {
          "extra": "tak nazyvájemyj, “so-called”",
          "word": "так называ́емый"
        }
      ],
      "categories": [
        "Russian abbreviations",
        "Russian adjectives",
        "Russian entries with incorrect language header",
        "Russian indeclinable adjectives",
        "Russian initialisms",
        "Russian lemmas",
        "Russian terms spelled with .",
        "Russian terms with redundant head parameter"
      ],
      "glosses": [
        "initialism of так называ́емый (tak nazyvájemyj, “so-called”)"
      ],
      "links": [
        [
          "так называ́емый",
          "так называемый#Russian"
        ],
        [
          "so-called",
          "so-called"
        ]
      ],
      "tags": [
        "abbreviation",
        "alt-of",
        "indeclinable",
        "initialism"
      ]
    }
  ],
  "synonyms": [
    {
      "roman": "t. naz.",
      "word": "т. наз."
    }
  ],
  "word": "т.н."
}