diff --git a/cyrus-imapd.spec b/cyrus-imapd.spec
index fbc9eff..15ed19a 100644
--- a/cyrus-imapd.spec
+++ b/cyrus-imapd.spec
@@ -200,6 +200,7 @@ tar xf %SOURCE81
 patch -p1 < %SOURCE90
 patch -p1 < %SOURCE91
 cp %SOURCE82 cassandane.ini
+# RF rpm-buildroot-usage
 sed -i \
     -e "s!CASSDIR!$(pwd)!" \
     -e "s!BUILDROOT!%buildroot!" \