diff --git a/mps/code/mpmtypes.h b/mps/code/mpmtypes.h
index d8ecc6596dd..167e8dea988 100644
--- a/mps/code/mpmtypes.h
+++ b/mps/code/mpmtypes.h
@@ -262,8 +262,8 @@ typedef Res (*LandFindInZonesMethod)(Bool *foundReturn, Range rangeReturn, Range
 /* CONSTANTS */
 
 
-/* <design/sig/> SIGnature IS BAD */
-#define SigInvalid      ((Sig)0x51915BAD)
+/* <design/sig/>  */
+#define SigInvalid      ((Sig)0x51915BAD) /* SIGnature IS BAD */
 
 #define SizeMAX         ((Size)-1)
 #define AccessSetEMPTY  ((AccessSet)0) /* <design/type/#access-set> */
diff --git a/mps/code/traceanc.c b/mps/code/traceanc.c
index 5326c5f2e21..f27c4fbe107 100644
--- a/mps/code/traceanc.c
+++ b/mps/code/traceanc.c
@@ -1,7 +1,7 @@
 /* traceanc.c: ANCILLARY SUPPORT FOR TRACER
  *
  * $Id$
- * Copyright (c) 2001-2014 Ravenbrook Limited.
+ * Copyright (c) 2001-2016 Ravenbrook Limited.
  * See end of file for license.
  * Portions copyright (C) 2002 Global Graphics Software.
  *
@@ -45,7 +45,7 @@
  * See <design/message-gc/>.
  */
 
-#define TraceStartMessageSig ((Sig)0x51926535) /* SIG TRaceStartMeSsage */
+#define TraceStartMessageSig ((Sig)0x51926535) /* SIGnature TRaceStartMeSsage */
 
 /* .whybuf:
  * .whybuf.len: Length (in chars) of a char buffer used to store the 
@@ -274,7 +274,7 @@ void TracePostStartMessage(Trace trace)
 
 /* TraceMessage -- type of trace end messages */
 
-#define TraceMessageSig ((Sig)0x51926359)
+#define TraceMessageSig ((Sig)0x51926359) /* SIGnature TRace MeSsaGe */
 
 typedef struct TraceMessageStruct  {
   Sig sig;
@@ -854,7 +854,7 @@ static void arenaForgetProtection(Globals globals)
 
 /* C. COPYRIGHT AND LICENSE
  *
- * Copyright (C) 2001-2014 Ravenbrook Limited
+ * Copyright (C) 2001-2016 Ravenbrook Limited
  * <http://www.ravenbrook.com/>.
  * All rights reserved.  This is an open source license.  Contact
  * Ravenbrook for commercial licensing options.
diff --git a/mps/code/walk.c b/mps/code/walk.c
index 0a4c51be88c..8e2a2187dc1 100644
--- a/mps/code/walk.c
+++ b/mps/code/walk.c
@@ -1,7 +1,7 @@
 /* walk.c: OBJECT WALKER
  *
  * $Id$
- * Copyright (c) 2001-2014 Ravenbrook Limited.  See end of file for license.
+ * Copyright (c) 2001-2016 Ravenbrook Limited.  See end of file for license.
  */
 
 #include "mpm.h"
@@ -14,7 +14,7 @@ SRCID(walk, "$Id$");
  */
 
 
-#define FormattedObjectsStepClosureSig ((Sig)0x519F05C1)
+#define FormattedObjectsStepClosureSig ((Sig)0x519F05C1) /* SIGnature Formatted Objects Step CLosure */
 
 typedef struct FormattedObjectsStepClosureStruct *FormattedObjectsStepClosure;
 
@@ -145,8 +145,7 @@ void mps_arena_formatted_objects_walk(mps_arena_t mps_arena,
  *
  * Defined as a subclass of ScanState.  */
 
-/* SIGnature Roots Step CLOsure */
-#define rootsStepClosureSig ((Sig)0x51965C10) 
+#define rootsStepClosureSig ((Sig)0x51965C10) /* SIGnature Roots Step CLOsure */
 
 typedef struct rootsStepClosureStruct *rootsStepClosure;
 typedef struct rootsStepClosureStruct {
@@ -391,7 +390,7 @@ void mps_arena_roots_walk(mps_arena_t mps_arena, mps_roots_stepper_t f,
 
 /* C. COPYRIGHT AND LICENSE
  *
- * Copyright (C) 2001-2014 Ravenbrook Limited <http://www.ravenbrook.com/>.
+ * Copyright (C) 2001-2016 Ravenbrook Limited <http://www.ravenbrook.com/>.
  * All rights reserved.  This is an open source license.  Contact
  * Ravenbrook for commercial licensing options.
  *