"\0" meaning in All languages combined

{
  "etymology_text": "From the escape sequence used in the C programming language and its numerous derivatives.",
  "head_templates": [
    {
      "args": {
        "1": "mul",
        "10": "",
        "2": "symbol",
        "3": "",
        "4": "",
        "5": "or",
        "6": "",
        "7": "or",
        "8": "",
        "9": "or",
        "cat2": "",
        "f1lang": "en",
        "f1nolink": "",
        "f2lang": "en",
        "f2nolink": "",
        "f3lang": "en",
        "f3nolink": "",
        "f4lang": "en",
        "f4nolink": "",
        "head": "",
        "head2": "",
        "head3": "",
        "head4": "",
        "sc": "Zsym",
        "sort": ""
      },
      "expansion": "\\0",
      "name": "head"
    },
    {
      "args": {},
      "expansion": "\\0",
      "name": "mul-symbol"
    }
  ],
  "lang": "Translingual",
  "lang_code": "mul",
  "pos": "symbol",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Translingual entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Translingual terms with non-redundant manual script codes",
          "parents": [
            "Terms with non-redundant manual script codes",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "mul",
          "name": "Programming",
          "orig": "mul:Programming",
          "parents": [
            "Computing",
            "Software engineering",
            "Technology",
            "Computer science",
            "Engineering",
            "Software",
            "All topics",
            "Sciences",
            "Applied sciences",
            "Media",
            "Fundamental",
            "Communication"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "Alternative form: \\000"
        }
      ],
      "glosses": [
        "A representation of the null character."
      ],
      "id": "en-\\0-mul-symbol-3IJJX-hy",
      "links": [
        [
          "programming",
          "programming#Noun"
        ],
        [
          "null",
          "null#English"
        ],
        [
          "character",
          "character#English"
        ]
      ],
      "raw_glosses": [
        "(programming) A representation of the null character."
      ],
      "topics": [
        "computing",
        "engineering",
        "mathematics",
        "natural-sciences",
        "physical-sciences",
        "programming",
        "sciences"
      ],
      "wikipedia": [
        "C (programming language)"
      ]
    }
  ],
  "word": "\\0"
}

{
  "etymology_text": "From the escape sequence used in the C programming language and its numerous derivatives.",
  "head_templates": [
    {
      "args": {
        "1": "mul",
        "10": "",
        "2": "symbol",
        "3": "",
        "4": "",
        "5": "or",
        "6": "",
        "7": "or",
        "8": "",
        "9": "or",
        "cat2": "",
        "f1lang": "en",
        "f1nolink": "",
        "f2lang": "en",
        "f2nolink": "",
        "f3lang": "en",
        "f3nolink": "",
        "f4lang": "en",
        "f4nolink": "",
        "head": "",
        "head2": "",
        "head3": "",
        "head4": "",
        "sc": "Zsym",
        "sort": ""
      },
      "expansion": "\\0",
      "name": "head"
    },
    {
      "args": {},
      "expansion": "\\0",
      "name": "mul-symbol"
    }
  ],
  "lang": "Translingual",
  "lang_code": "mul",
  "pos": "symbol",
  "senses": [
    {
      "categories": [
        "Translingual entries with incorrect language header",
        "Translingual lemmas",
        "Translingual symbols",
        "Translingual terms spelled with \\",
        "Translingual terms spelled with numbers",
        "Translingual terms with non-redundant manual script codes",
        "mul:Programming"
      ],
      "examples": [
        {
          "text": "Alternative form: \\000"
        }
      ],
      "glosses": [
        "A representation of the null character."
      ],
      "links": [
        [
          "programming",
          "programming#Noun"
        ],
        [
          "null",
          "null#English"
        ],
        [
          "character",
          "character#English"
        ]
      ],
      "raw_glosses": [
        "(programming) A representation of the null character."
      ],
      "topics": [
        "computing",
        "engineering",
        "mathematics",
        "natural-sciences",
        "physical-sciences",
        "programming",
        "sciences"
      ],
      "wikipedia": [
        "C (programming language)"
      ]
    }
  ],
  "word": "\\0"
}