rpn compare operators CAN return unknown ... (#293)

[rrdtool.git] / doc / rrdgraph_rpn.pod

diff --git a/doc/rrdgraph_rpn.pod b/doc/rrdgraph_rpn.pod
index 16f7610..5558c22 100644 (file)
--- a/doc/rrdgraph_rpn.pod
+++ b/doc/rrdgraph_rpn.pod
@@ -51,7 +51,8 @@ B<LT, LE, GT, GE, EQ, NE>
 
 Pop two elements from the stack, compare them for the selected condition
 and return 1 for true or 0 for false. Comparing an I<unknown> or an
-I<infinite> value will always result in 0 (false).
+I<infinite> value will result in I<unknown> returned ... which will also be
+treated as false by the B<IF> call.
 
 B<UN, ISINF>