diff --git a/src/conf.py b/src/conf.py
index 1e2df0ebe..4770f1592 100644
--- a/src/conf.py
+++ b/src/conf.py
@@ -424,15 +424,13 @@ def registerNetwork(name, password='', ssl=True, sasl_username='',
         connecting a server (IRC, HTTP, ...) via IPv4. If empty, defaults to
         supybot.protocols.irc.vhost. It must be (or resolve to) an IP address
         assigned to one of the network interfaces (see 'ip addr' on Linux).
-        This may differ from the hostname visible on IRC, which is based on the
-        outgoing IP address or the reverse-DNS of that IP address.""")))
+        This may differ from the bot's public IP address, if it is behind a NAT.""")))
     registerGlobalValue(network, 'vhostv6',
         registry.String('', _("""Determines what vhost the bot will bind to before
         connecting a server (IRC, HTTP, ...) via IPv6. If empty, defaults to
         supybot.protocols.irc.vhostv6. It must be (or resolve to) an IP address
         assigned to one of the network interfaces (see 'ip addr' on Linux).
-        This may differ from the hostname visible on IRC, which is based on the
-        outgoing IP address or the reverse-DNS of that IP address.""")))
+        This may differ from the bot's public IP address, if it is behind a NAT.""")))
 
     sasl = registerGroup(network, 'sasl')
     registerGlobalValue(sasl, 'username', registry.String(sasl_username,
@@ -1372,16 +1370,14 @@ registerGlobalValue(supybot.protocols.irc, 'vhost',
     connecting a server (IRC, HTTP, ...) via IPv4. It must be (or resolve to)
     an IP address assigned to one of the network interfaces (see 'ip addr' on
     Linux).
-    This may differ from the hostname visible on IRC, which is based on the
-    outgoing IP address or the reverse-DNS of that IP address.""")))
+    This may differ from the bot's public IP address, if it is behind a NAT.""")))
 
 registerGlobalValue(supybot.protocols.irc, 'vhostv6',
     registry.String('', _("""Determines what vhost the bot will bind to before
     connecting a server (IRC, HTTP, ...) via IPv6. It must be (or resolve to)
     an IP address assigned to one of the network interfaces (see 'ip -6 addr' on
     Linux).
-    This may differ from the hostname visible on IRC, which is based on the
-    outgoing IP address or the reverse-DNS of that IP address.""")))
+    This may differ from the bot's public IP address, if it is behind a NAT.""")))
 
 registerGlobalValue(supybot.protocols.irc, 'maxHistoryLength',
     registry.Integer(1000, _("""Determines how many old messages the bot will