Hi, I'm looking into Linux kernel source and have found some declarations like that: static struct file_operations apm_bios_fops = { .owner = THIS_MODULE, .read = do_read, .poll = do_poll, .ioctl = do_ioctl, .open = do_open, .release = do_release, }; After refering to Linux Device Driver 2nd Edtion, I got a term -- "tagged initialization format". The only thing I could figure out from this book is that, this is an extension of GCC and it can enhance the portability of structure definitions. However when I tended to GCC infopage, I could hardly find a word about that? Anybody can help to explain that, or direct me to the appropriate documents? Thanks a lot.