Add Mark Dickinson for SF # 1675423.
diff --git a/Misc/ACKS b/Misc/ACKS
index 2670c3b..0cbca31 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -160,6 +160,7 @@
 Erik Demaine
 Roger Dev
 Toby Dickenson
+Mark Dickinson
 Yves Dionne
 Daniel Dittmar
 Walter Dörwald