If for some reason you need to disable automatic conversion of underscores to hyphens, set the parameter `convert_underscores` of `Header` to `False`:

{* ../../docs_src/header_params/tutorial002_an_py310.py hl[10] *}

/// warning

Before setting `convert_underscores` to `False`, bear in mind that some HTTP proxies and servers disallow the usage of headers with underscores.

///

## Duplicate headers { #duplicate-headers }

            "loc": ["header", "tool"],
            "msg": "Extra inputs are not permitted",
            "input": "plumbus",
        }
    ]
}
```

## Desativar conversão de underscores { #disable-convert-underscores }

Da mesma forma que com parâmetros de cabeçalho normais, quando você tem caracteres de sublinhado nos nomes dos parâmetros, eles são **automaticamente convertidos em hifens**.

            "msg": "Extra inputs are not permitted",
            "input": "plumbus",
        }
    ]
}
```

## Как отключить автоматическое преобразование подчеркиваний { #disable-convert-underscores }

Как и в случае с обычными заголовками, если у вас в именах параметров имеются символы подчеркивания, они **автоматически преобразовываются в дефис**.

            "loc": ["header", "tool"],
            "msg": "Extra inputs are not permitted",
            "input": "plumbus",
        }
    ]
}
```

## Desactivar la conversión de guiones bajos { #disable-convert-underscores }

De la misma forma que con los parámetros de header normales, cuando tienes caracteres de guion bajo en los nombres de los parámetros, se **convierten automáticamente en guiones**.

        Files.writeString(specialDir.resolve("file-with-dashes.txt"), "dashes");
        Files.writeString(specialDir.resolve("file_with_underscores.txt"), "underscores");
        Files.writeString(specialDir.resolve("file.multiple.dots.txt"), "dots");

        // Setup deeply nested directories
        Path currentDir = deepDir;
        for (int i = 1; i <= 5; i++) {

        this.logLevel = logLevel;
        return this;
    }

    /**
     * Sets the log suffix for this job execution.
     * The suffix is trimmed and whitespace is replaced with underscores.
     *
     * @param logSuffix the suffix to append to log file names
     * @return this ExecJob instance for method chaining
     */
    public ExecJob logSuffix(final String logSuffix) {

        }
        return value;
    }

    /**
     * Replaces special characters in a string with underscores for group names.
     *
     * @param value the string to process
     * @return the string with special characters replaced by underscores
     */
    protected String replaceWithUnderscores(final String value) {
        return value.replaceAll("[/\\\\\\[\\]:;|=,+\\*?<>]", "_");

            """
        ),
    ] = None,
    convert_underscores: Annotated[
        bool,
        Doc(
            """
            Automatically convert underscores to hyphens in the parameter field name.

            Read more about it in the
            [FastAPI docs for Header Parameters](https://fastapi.tiangolo.com/tutorial/header-params/#automatic-conversion)
            """

     */
    boolean isLdapIgnoreNetbiosName();

    /**
     * Get the value for the key 'ldap.group.name.with.underscores'. <br>
     * The value is, e.g. false <br>
     * comment: Whether to allow underscores in LDAP group names.
     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     */
    String getLdapGroupNameWithUnderscores();

            {"strange_header": "FastAPI test"},
            200,
            {"strange_header": "FastAPI test"},
        ),
        (
            "/items",
            {"strange-header": "Not really underscore"},
            200,
            {"strange_header": None},
        ),
    ],
)
def test(path, headers, expected_status, expected_response, client: TestClient):
    response = client.get(path, headers=headers)