# File lib/yard/templates/helpers/html_helper.rb, line 527
      def charset
        has_encoding = defined?(::Encoding)
        if @file && has_encoding
          lang = @file.contents.encoding.to_s
        else
          return 'utf-8' unless has_encoding || lang = ENV['LANG']
          if has_encoding
            lang = ::Encoding.default_external.name.downcase
          else
            lang = lang.downcase.split('.').last
          end
        end
        case lang
        when "ascii-8bit", "us-ascii", "ascii-7bit"; 'iso-8859-1'
        when "utf8"; 'utf-8'
        else; lang
        end
      end