-The glibc implementation allows a complete reset of the environment,
-including re-checking for @env{POSIXLY_CORRECT}, by setting
-@code{optind} to 0. Other implementations provide @code{optreset},
-causing a reset by setting it non-zero, although it does not
-necessarily re-read @env{POSIXLY_CORRECT}.
+Some implementations return success instead of reporting an ambiguity
+if user's option is a prefix of two long options with the same outcome:
+FreeBSD.
+@item
+The GNU Coding Standards discourage the use of @code{getopt_long_only}
+in new programs.