diff --git a/doc/src/sgml/ref/create_function.sgml b/doc/src/sgml/ref/create_function.sgml
index c5beb166cf..cc2098c442 100644
--- a/doc/src/sgml/ref/create_function.sgml
+++ b/doc/src/sgml/ref/create_function.sgml
@@ -350,9 +350,18 @@ CREATE [ OR REPLACE ] FUNCTION
effects. It reveals no information about its arguments other than by
its return value. For example, a function which throws an error message
for some argument values but not others, or which includes the argument
- values in any error message, is not leakproof. The query planner may
- push leakproof functions (but not others) into views created with the
- security_barrier option. See
+ values in any error message, is not leakproof. This affects how the
+ system executes queries against views created with the
+ security_barrier option or tables with row level
+ security enabled. The system will enforce conditions from security
+ policies and security barrier views before any user-supplied conditions
+ from the query itself that contain non-leakproof functions, in order to
+ prevent the inadvertent exposure of data. Functions and operators
+ marked as leakproof are assumed to be trustworthy, and may be executed
+ before conditions from security policies and security barrier views.
+ In addtion, functions which do not take arguments or which are not
+ passed any arguments from the security barrier view or table do not have
+ to be marked as leakproof to be executed before security conditions. See
and .
This option can only be set by the superuser.