GNU double-dash long options were devised only after POSIX disallowed using the plus sign in 1992: https://blog.djmnet.org/2019/08/02/why-do-long-options-start-

GNU double-dash long options were devised only after POSIX disallowed using the plus sign in 1992: https://blog.djmnet.org/2019/08/02/why-do-long-options-start-with/ https://blog.djmnet.org/2019/08/02/why-do-long-options-start... Java was already two years in development at that time.