code: function vchar() {
          return wrap('vchar', compareToken(function vcharFunc(tok) {
              var code = tok.charCodeAt(0);
              var accept = (0x21 <= code && code <= 0x7E);
              if (opts.rfc6532) {
                  accept = accept || isUTF8NonAscii(tok);
              }
              return accept;
          }));
      }
docs: VCHAR          =  %x21-7E ; visible (printing) characters