thank you for your reply. i am fully aware of the history of bitsetting, ive done the research, i do know how to use google you know. just making fun.
now ive never tried actually using imgBurns or Benqs booktype utilities. i use modified firmware from others or by using MCSE and have imgburn set to automatically booktype when available. this has always worked for +r media bitsetting the first four bits of the booktype field with 0000, thus my +r disc would read physical format of +r but booktype DVD-ROM. i am fully aware of the bitsetting to achieve the desired booktype, 0001 DVD-RAM, 0010 DVD-R or DVD-R DL, 0011 DVD-RW, 1001 DVD+RW, 1010 DVD+R, 1101 DVD+RW DL and 1110 DVD+R DL. remember i said i know how to use google.
being fully aware of the bitsetting options, i was not aware any drive actually supported bitsetting other than DVD-ROM, with the exception of changing dvd+rw to dvd-rom and back to dvd+rw. thus i was very surprised when i was presented with the screen shot of BenQ booktype settings having many options.
to me the option of using a BenQ drive to bitset +r/+rw media to -r is a gimmick, the disc was only readable by the BenQ drive. however when the booktype of the +rw was changed back to +rw or changed to +r my other drives did properly recognize the disc and read the data ImgBurn had written. there is no mention of the -r option in the BenQ BookType Management Tool FAQ sheet, nor any mention of -r bitsetting on the DVD+RW alliance or DVDplusRW web sites.