doc: add manpage for libxt_osf
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
diff --git a/extensions/libxt_osf.c b/extensions/libxt_osf.c
index 3c0ea2d..07b86e4 100644
--- a/extensions/libxt_osf.c
+++ b/extensions/libxt_osf.c
@@ -40,8 +40,8 @@
static void osf_help(void)
{
printf("OS fingerprint match options:\n"
- "--genre [!] string Match a OS genre by passive fingerprinting.\n"
- "--ttl Use some TTL check extensions to determine OS:\n"
+ "[!] --genre string Match a OS genre by passive fingerprinting.\n"
+ "--ttl level Use some TTL check extensions to determine OS:\n"
" 0 true ip and fingerprint TTL comparison. Works for LAN.\n"
" 1 check if ip TTL is less than fingerprint one. Works for global addresses.\n"
" 2 do not compare TTL at all. Allows to detect NMAP, but can produce false results.\n"