- * opt_register_table()/opt_register_arg()/opt_register_noarg(). If there
- * are unknown options, missing arguments or a callback returns false, then
- * an error message is printed and false is returned.
+ * opt_register_table()/opt_register_arg()/opt_register_noarg(). As this
+ * occurs successfully each option is removed from argc and argv.
+ *
+ * If there are unknown options, missing arguments or a callback
+ * returns false, then an error message is printed and false is
+ * returned: the erroneous option is not removed.