Issue #13522: document error return values of some float and complex C API functions.
diff --git a/Misc/ACKS b/Misc/ACKS
index 44e92c1..8c8b9b8 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -120,6 +120,7 @@
 Lee Busby
 Ralph Butler
 Jp Calderone
+Arnaud Calmettes
 Daniel Calvelo
 Tony Campbell
 Brett Cannon