6.4.1 Keywords

      keyword: one of
        auto        enum        restrict    unsigned
        break       extern      return      void
        case        float       short       volatile
        char        for         signed      while
        const       goto        sizeof      _Bool
        continue    if          static      _Complex
        default     inline      struct      _Imaginary
        do          int         switch
        double      long        typedef
        else        register    union

784 The above tokens (case sensitive) are reserved (in translation phases 7 and 8) for use as keywords, and shall not be used otherwise.

785 The keyword _Imaginary is reserved for specifying imaginary types.⁵⁹⁾

786 59) One possible specification for imaginary types appears in Annex G.