diff --git a/doc/src/sgml/client-auth.sgml b/doc/src/sgml/client-auth.sgml
index a2c04948b27..c05805b1d28 100644
--- a/doc/src/sgml/client-auth.sgml
+++ b/doc/src/sgml/client-auth.sgml
@@ -241,7 +241,9 @@ hostnossl database user
172.20.143.89/32 for a single host, or
172.20.143.0/24 for a small network, or
10.6.0.0/16 for a larger one.
- 0.0.0.0/0 (all balls>) represents all addresses.
+ 0.0.0.0/0 (all balls>) represents all
+ IPv4 addresses, and :: represents
+ all IPv6 addresses.
To specify a single host, use a CIDR mask of 32 for IPv4 or
128 for IPv6. In a network address, do not omit trailing zeroes.