[spec] Clarification: Are symbols not listed in `__all__` ever considered public?

According to https://typing.readthedocs.io/en/latest/guides/libraries.html#library-interface-public-and-private-symbols:

A module can expose an __all__ symbol at the module level that provides a list of names that are considered part of the interface. This overrides all other rules above, allowing imported symbols or symbols whose names begin with an underscore to be included in the interface.

Does this mean that if __all__ is present: ① A symbol is public if and only if it is listed in __all__ or ② If a symbol is listed in __all__, it is public, but things not listed in __all__ can still be considered public as well?

For example:

# module.py
__all__ = ["identity"]

from typing import TypeVar

T = TypeVar("T")

def identity(x: T) -> T:
    return x

Are TypeVar and T considered public members of module.py? If so, what is the suggested way to exclude them? T could be renamed to _T, but is one supposed to do from typing import TypeVar as _TypeVar, if one wants TypeVar to not be considered a public member of module?

从链接的《Library Interface: Public and Private Symbols》指南开始，并将其中关于 all 的表述与 issue 中的 module.py 示例进行比较。完成的标准是：文档明确说明公开符号的行为，包括在适当情况下应如何排除导入的名称和 TypeVar 声明。