diff --git a/plotutils.spec b/plotutils.spec
index 9749cc6..2e9fe98 100644
--- a/plotutils.spec
+++ b/plotutils.spec
@@ -37,6 +37,7 @@ Patch:          plotutils-man.patch
 Patch1:         plotutils-uninitialized.patch
 Patch2:         plotutils-dasharray-format.patch
 Patch3:         plotutils-autoreconf.patch
+# libpng15.patch sent 2012-08-30 at rsm@math.arizona.edu
 Patch4:         plotutils-libpng15.patch
 BuildRoot:      %{_tmppath}/%{name}-%{version}-build