diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index e397386..6d9d531 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -836,7 +836,9 @@
         <literal><function>random()</function></literal>
        </entry>
        <entry><type>dp</type></entry>
-       <entry>random value in the range 0.0 &lt;= x &lt; 1.0</entry>
+       <entry>pseudo-random value in the range 0.0 &lt;= x &lt; 1.0
+       (characteristic of randomness depends on the system implementation
+       and is usually limited, thus not considered as a CSPRNG in any case)</entry>
        <entry><literal>random()</literal></entry>
        <entry></entry>
       </row>