diff --git a/doc/src/sgml/ref/create_domain.sgml b/doc/src/sgml/ref/create_domain.sgml
index 1c3eb357c0442c58ef5f8fdbefbdab26fcabe06f..bddfb572875c806c6f9108f7bfe714910d600af5 100644
--- a/doc/src/sgml/ref/create_domain.sgml
+++ b/doc/src/sgml/ref/create_domain.sgml
@@ -1,5 +1,5 @@
@@ -48,10 +48,13 @@ where constraint is:
- Domains are useful for abstracting common fields between tables into
- a single location for maintenance. For example, an email address column may be used
- in several tables, all with the same properties. Define a domain and
- use that rather than setting up each table's constraints individually.
+ Domains are useful for abstracting common fields between tables
+ into a single location for maintenance. For example, an email address
+ column may be used in several tables, all with the same properties.
+ Define a domain and use that rather than setting up each table's
+ constraints individually. Keep in mind also that declaring a
+ function result value as a domain is pretty dangerous, because none of
+ the PLs enforce domain constraints on their results.