diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 13c71af..da30991 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -924,6 +924,25 @@
+
+ For functions like round(), log() and sqrt() which run against
+ either fixed-precision (NUMERIC) or floating-point numbers (e.g. REAL),
+ note that the results of these operations will differ according
+ to the input type due to rounding. This is most observable with
+ round(), which can end up rounding down as well as up for
+ any #.5 value. We use the
+ IEEE's rules
+ for rounding floating-point numbers which can be machine-specific.
+ The bitwise operators work only on integral data types, whereas
+ the others are available for all numeric data types.
+
+
+
+ The bitwise operators are also available for the bit string types
+ bit and bit varying, as
+ shown in .
+
+
shows functions for
generating random numbers.