https://github.com/llvm/llvm-project/blame/665457815f11118f7e755a471f33606c8562a4be/clang-tools-extra/docs/clang-tidy/checks/bugprone/reserved-identifier.rst#L31 used _not_.

As per https://docutils.sourceforge.io/docs/user/rst/quickref.html#inline-markup, it probably should be *not*.