diff --git a/doc/rrdgraph_rpn.pod b/doc/rrdgraph_rpn.pod
index 3718349cdbba42e80e991fb461511675cf18b48c..aabd7383e43979ae6396d0fc210aa3c879a55563 100644 (file)
--- a/doc/rrdgraph_rpn.pod
+++ b/doc/rrdgraph_rpn.pod
Add, subtract, multiply, divide, modulo
+B<ADDNAN>
+
+NAN-safe addition. If one parameter is NAN/UNKNOWN it'll be treated as
+zero. If both parameters are NAN/UNKNOWN, NAN/UNKNOWN will be returned.
+
B<SIN, COS, LOG, EXP, SQRT>
Sine and cosine (input in radians), log and exp (natural logarithm),