query: str = Query(default=..., max_length=10),
    session: str = Cookie(default=..., min_length=3),
    x_trace: str = Header(default=..., title="Tracing header"),
):
    return {"message": "Hello World"}
```

...all these parameters are required because the default value is `...` (Ellipsis).

203E          ; disallowed_STD3_mapped ; 0020 0305     # 1.1  OVERLINE
203F..2046    ; valid                  ;      ; NV8    # 1.1  UNDERTIE..RIGHT SQUARE BRACKET WITH QUILL
2047          ; disallowed_STD3_mapped ; 003F 003F     # 3.2  DOUBLE QUESTION MARK
2048          ; disallowed_STD3_mapped ; 003F 0021     # 3.0  QUESTION EXCLAMATION MARK