diff --git a/detectors/cds/params/ycf1 b/detectors/cds/params/ycf1
new file mode 100644
index 0000000000000000000000000000000000000000..c9d14bbf9f3a660cd644579b354dbde8f2dbb728
--- /dev/null
+++ b/detectors/cds/params/ycf1
@@ -0,0 +1,4 @@
+#
+# pass1: exonerate parameters
+#
+AssignUndef PASS1_PERCENT       10