update man for -6

man/3proxy.cfg.3

@@ -135,7 +135,7 @@ Never ask for username/password
 (for proxy) - generate Via: and X-Forwared-For: instead of Forwarded:
 .br
 .B -6
-Only resolve IPv6 addresses
+Only resolve IPv6 addresses. IPv4 addresses are packed in IPv6 in IPV6_V6ONLY compatible way.
 .br
 .B -4
 Only resolve IPv4 addresses