add Mark Shannon
diff --git a/Misc/ACKS b/Misc/ACKS
index 6eedfc3..079386e 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -847,6 +847,7 @@
 Denis Severson
 Ian Seyer
 Ha Shao
+Mark Shannon
 Richard Shapiro
 Bruce Sherwood
 Alexander Shigin