diff --git a/libguile/numbers.h b/libguile/numbers.h
index b343d3653..96bd5e2f1 100644
--- a/libguile/numbers.h
+++ b/libguile/numbers.h
@@ -97,10 +97,10 @@
 
 /* SCM_FIXABLE is non-0 if its long argument can be encoded in an SCM_INUM.
  */
-#define SCM_POSSCM_FIXABLE(n) ((n) <= SCM_MOST_POSITIVE_FIXNUM)
-#define SCM_NEGSCM_FIXABLE(n) ((n) >= SCM_MOST_NEGATIVE_FIXNUM)
-#define SCM_UNEGSCM_FIXABLE(n) ((n) <= -SCM_MOST_NEGATIVE_FIXNUM)
-#define SCM_FIXABLE(n) (SCM_POSSCM_FIXABLE(n) && SCM_NEGSCM_FIXABLE(n))
+#define SCM_POSFIXABLE(n) ((n) <= SCM_MOST_POSITIVE_FIXNUM)
+#define SCM_NEGFIXABLE(n) ((n) >= SCM_MOST_NEGATIVE_FIXNUM)
+#define SCM_UNEGFIXABLE(n) ((n) <= -SCM_MOST_NEGATIVE_FIXNUM)
+#define SCM_FIXABLE(n) (SCM_POSFIXABLE(n) && SCM_NEGFIXABLE(n))
 
 /* SCM_INTBUFLEN is the maximum number of characters neccessary for the
  * printed or scm_string representation of an exact immediate.
@@ -167,7 +167,7 @@
 # define SCM_DIGSPERLONG ((scm_sizet)((sizeof(long)*SCM_CHAR_BIT+SCM_BITSPERDIG-1)/SCM_BITSPERDIG))
 # define SCM_DIGSPERLONGLONG ((scm_sizet)((sizeof(long long)*SCM_CHAR_BIT+SCM_BITSPERDIG-1)/SCM_BITSPERDIG))
 # define SCM_BIGUP(x) ((unsigned long)(x) << SCM_BITSPERDIG)
-# define SCM_LONGLONGSCM_BIGUP(x) ((ulong_long)(x) << SCM_BITSPERDIG)
+# define SCM_LONGLONGBIGUP(x) ((ulong_long)(x) << SCM_BITSPERDIG)
 # define SCM_BIGDN(x) ((x) >> SCM_BITSPERDIG)
 # define SCM_BIGLO(x) ((x) & (SCM_BIGRAD-1))
 #endif /* def BIGNUMS */
@@ -177,7 +177,7 @@
  * prototypes to compile with conditionalization.
  */
 # define SCM_BIGDIG unsigned short
-# define NO_SCM_BIGDIG
+# define SCM_NO_BIGDIG
 # ifndef SCM_FLOATS
 #  define SCM_INUMS_ONLY
 # endif /* ndef SCM_FLOATS */
diff --git a/libguile/print.c b/libguile/print.c
index 805f92c25..603f72117 100644
--- a/libguile/print.c
+++ b/libguile/print.c
@@ -225,7 +225,7 @@ taloop:
 	}
       else if (SCM_IFLAGP (exp)
 	       && (SCM_ISYMNUM (exp) < (sizeof scm_isymnames / sizeof (char *))))
-	  scm_gen_puts (scm_regular_string, SCM_ISYMSCM_CHARS (exp), port);
+	  scm_gen_puts (scm_regular_string, SCM_ISYMCHARS (exp), port);
       else if (SCM_ILOCP (exp))
 	{
 	  scm_gen_puts (scm_regular_string, "#@", port);
@@ -296,7 +296,7 @@ taloop:
 	    {
 	      SCM code = SCM_CODE (exp);
 	      exp = scm_unmemocopy (code,
-				    SCM_EXTEND_SCM_ENV (SCM_CAR (code),
+				    SCM_EXTEND_ENV (SCM_CAR (code),
 							SCM_EOL,
 							SCM_ENV (exp)));
 	      scm_iprlist ("#<CLOSURE ", exp, '>', port, writing);
diff --git a/libguile/scmhob.h b/libguile/scmhob.h
index b245cbabb..063938d90 100644
--- a/libguile/scmhob.h
+++ b/libguile/scmhob.h
@@ -131,7 +131,7 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 #define CHCI_LESSP(x,y) ((upcase[SCM_ICHR(x)] < upcase[SCM_ICHR(y)]) ? SCM_BOOL_T : SCM_BOOL_F)
 #define CHCI_LEQP(x,y) ((upcase[SCM_ICHR(x)] <= upcase[SCM_ICHR(y)]) ? SCM_BOOL_T : SCM_BOOL_F)
 #define CHAR_ALPHAP(chr) ((isascii(SCM_ICHR(chr)) && isalpha(SCM_ICHR(chr))) ? SCM_BOOL_T : SCM_BOOL_F)
-#define CHAR_SCM_NUMP(chr) ((isascii(SCM_ICHR(chr)) && isdigit(SCM_ICHR(chr))) ? SCM_BOOL_T : SCM_BOOL_F)
+#define SCM_CHAR_NUMP(chr) ((isascii(SCM_ICHR(chr)) && isdigit(SCM_ICHR(chr))) ? SCM_BOOL_T : SCM_BOOL_F)
 #define CHAR_WHITEP(chr) ((isascii(SCM_ICHR(chr)) && isspace(SCM_ICHR(chr))) ? SCM_BOOL_T : SCM_BOOL_F)
 #define CHAR_UPPERP(chr) ((isascii(SCM_ICHR(chr)) && isupper(SCM_ICHR(chr))) ? SCM_BOOL_T : SCM_BOOL_F)
 #define CHAR_LOWERP(chr) ((isascii(SCM_ICHR(chr)) && islower(SCM_ICHR(chr))) ? SCM_BOOL_T : SCM_BOOL_F)
@@ -139,9 +139,9 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 #define INT2CHAR(n) SCM_MAKICHR(SCM_INUM(n))
 #define CHAR_UPCASE(chr) SCM_MAKICHR(upcase[SCM_ICHR(chr)])
 #define CHAR_DOWNCASE(chr) SCM_MAKICHR(downcase[SCM_ICHR(chr)])
-#define ST_SCM_LENGTH(str) SCM_MAKINUM(SCM_LENGTH(str))
+#define ST_LENGTH(str) SCM_MAKINUM(SCM_LENGTH(str))
 #define ST_REF(str,k) SCM_MAKICHR(SCM_CHARS(str)[SCM_INUM(k)])
-#define VECTOR_SCM_LENGTH(v)  SCM_MAKINUM(SCM_LENGTH(v))
+#define VECTOR_LENGTH(v)  SCM_MAKINUM(SCM_LENGTH(v))
 
 #ifdef SCM_FLOATS
 #include <math.h>
diff --git a/libguile/simpos.h b/libguile/simpos.h
index d041ec491..929dc6b61 100644
--- a/libguile/simpos.h
+++ b/libguile/simpos.h
@@ -1,7 +1,7 @@
 /* classes: h_files */
 
-#ifndef SSCM_IMPOSH
-#define SSCM_IMPOSH
+#ifndef SIMPOSH
+#define SIMPOSH
 /*	Copyright (C) 1995,1996 Free Software Foundation, Inc.
  * 
  * This program is free software; you can redistribute it and/or modify
@@ -64,4 +64,4 @@ extern void scm_init_simpos ();
 
 
 
-#endif  /* SSCM_IMPOSH */
+#endif  /* SIMPOSH */
diff --git a/libguile/symbols.c b/libguile/symbols.c
index 338606fc5..bf694f99c 100644
--- a/libguile/symbols.c
+++ b/libguile/symbols.c
@@ -291,7 +291,7 @@ scm_intern_obarray_soft (name, len, obarray, softness)
   lsym = scm_makfromstr (name, len, SCM_SYMBOL_SLOTS);
 
   SCM_SETLENGTH (lsym, (long) len, scm_tc7_msymbol);
-  SCM_SYMBOL_MULTI_BYTE_SCM_STRINGP (lsym) = SCM_BOOL_F;
+  SCM_SYMBOL_MULTI_BYTE_STRINGP (lsym) = SCM_BOOL_F;
   SCM_SYMBOL_HASH (lsym) = scm_hash;
   if (obarray == SCM_BOOL_F)
     {
@@ -446,9 +446,9 @@ scm_string_to_symbol(s)
   if (SCM_TYP7 (answer) == scm_tc7_msymbol)
     {
       if (SCM_REGULAR_STRINGP (s))
-	SCM_SYMBOL_MULTI_BYTE_SCM_STRINGP (answer) = SCM_BOOL_F;
+	SCM_SYMBOL_MULTI_BYTE_STRINGP (answer) = SCM_BOOL_F;
       else
-	SCM_SYMBOL_MULTI_BYTE_SCM_STRINGP (answer) = SCM_BOOL_T;
+	SCM_SYMBOL_MULTI_BYTE_STRINGP (answer) = SCM_BOOL_T;
     }
   return answer;
 }
@@ -488,9 +488,9 @@ scm_string_to_obarray_symbol(o, s, softp)
   if (SCM_TYP7 (s) == scm_tc7_msymbol)
     {
       if (SCM_REGULAR_STRINGP (s))
-	SCM_SYMBOL_MULTI_BYTE_SCM_STRINGP (answer) = SCM_BOOL_F;
+	SCM_SYMBOL_MULTI_BYTE_STRINGP (answer) = SCM_BOOL_F;
       else
-	SCM_SYMBOL_MULTI_BYTE_SCM_STRINGP (answer) = SCM_BOOL_T;
+	SCM_SYMBOL_MULTI_BYTE_STRINGP (answer) = SCM_BOOL_T;
     }
   return answer;
 }
@@ -678,7 +678,7 @@ msymbolize (s)
   string = scm_makfromstr (SCM_CHARS (s), SCM_LENGTH (s), SCM_SYMBOL_SLOTS);
   SCM_SETCHARS (s, SCM_CHARS (string));
   SCM_SETLENGTH (s, SCM_LENGTH (s), scm_tc7_msymbol);
-  SCM_SYMBOL_MULTI_BYTE_SCM_STRINGP (s) = SCM_BOOL_F;
+  SCM_SYMBOL_MULTI_BYTE_STRINGP (s) = SCM_BOOL_F;
   SCM_CDR (string) = SCM_EOL;
   SCM_CAR (string) = SCM_EOL;
 }
diff --git a/libguile/symbols.h b/libguile/symbols.h
index aa6e35735..9fe29e364 100644
--- a/libguile/symbols.h
+++ b/libguile/symbols.h
@@ -61,7 +61,7 @@ extern int scm_symhash_dim;
 #define SCM_SYMBOL_FUNC(X) (SCM_SLOTS(X)[0])
 #define SCM_SYMBOL_PROPS(X) (SCM_SLOTS(X)[1])
 #define SCM_SYMBOL_HASH(X) (*(unsigned long*)(&SCM_SLOTS(X)[2]))
-#define SCM_SYMBOL_MULTI_BYTE_SCM_STRINGP(X) (*(unsigned long*)(&SCM_SLOTS(X)[3]))
+#define SCM_SYMBOL_MULTI_BYTE_STRINGP(X) (*(unsigned long*)(&SCM_SLOTS(X)[3]))
 
 #define SCM_ROSTRINGP(x) ((SCM_TYP7SD(x)==scm_tc7_string) || (SCM_TYP7S(x) == scm_tc7_ssymbol))
 #define SCM_ROCHARS(x) ((SCM_TYP7(x) == scm_tc7_substring) \
diff --git a/libguile/tags.h b/libguile/tags.h
index c230f5c32..0c517a7b5 100644
--- a/libguile/tags.h
+++ b/libguile/tags.h
@@ -431,7 +431,7 @@ enum scm_tags
 /* SCM_IFLAGP tests for ISPCSYM, ISYM and IFLAG */
 #define SCM_IFLAGP(n) 		((0x87 & (int)(n))==4)
 #define SCM_ISYMNUM(n) 		((int)((n)>>9))
-#define SCM_ISYMSCM_CHARS(n) 	(scm_isymnames[SCM_ISYMNUM(n)])
+#define SCM_ISYMCHARS(n) 	(scm_isymnames[SCM_ISYMNUM(n)])
 #define SCM_MAKSPCSYM(n) 	(((n)<<9)+((n)<<3)+4L)
 #define SCM_MAKISYM(n) 		(((n)<<9)+0x74L)
 #define SCM_MAKIFLAG(n) 	(((n)<<9)+0x174L)
diff --git a/libguile/throw.c b/libguile/throw.c
index 9b2818701..7be2f1b55 100644
--- a/libguile/throw.c
+++ b/libguile/throw.c
@@ -71,9 +71,9 @@ SCM scm_bad_throw_vcell;
 #define JBJMPBUF(O) ((jmp_buf*)SCM_CDR (O) )
 #define SETJBJMPBUF SCM_SETCDR
 #else
-#define JBSCM_DFRAME(O) ((scm_debug_frame*)SCM_CAR (SCM_CDR (O)) )
+#define SCM_JBDFRAME(O) ((scm_debug_frame*)SCM_CAR (SCM_CDR (O)) )
 #define JBJMPBUF(O) ((jmp_buf*)SCM_CDR (SCM_CDR (O)) )
-#define SETJBSCM_DFRAME(O,X) SCM_CAR(SCM_CDR (O)) = (SCM)(X)
+#define SCM_SETJBDFRAME(O,X) SCM_CAR(SCM_CDR (O)) = (SCM)(X)
 #define SETJBJMPBUF(O,X) SCM_SETCDR(SCM_CDR (O), X)
 
 #ifdef __STDC__
@@ -174,7 +174,7 @@ scm_catch (tag, thunk, handler)
   scm_dynwinds = scm_acons (tag, jmpbuf, scm_dynwinds);
   SETJBJMPBUF(jmpbuf, &jbr.buf);
 #ifdef DEBUG_EXTENSIONS
-  SETJBSCM_DFRAME(jmpbuf, last_debug_info_frame);
+  SCM_SETJBDFRAME(jmpbuf, last_debug_info_frame);
 #endif
   if (setjmp (jbr.buf))
     {
@@ -287,7 +287,7 @@ scm_ithrow (key, args, noreturn)
   }
   scm_dowinds (wind_goal, scm_ilength (scm_dynwinds) - scm_ilength (wind_goal));
 #ifdef DEBUG_EXTENSIONS
-  last_debug_info_frame = JBSCM_DFRAME (jmpbuf);
+  last_debug_info_frame = SCM_JBDFRAME (jmpbuf);
 #endif
   longjmp (*JBJMPBUF (jmpbuf), 1);
 }
diff --git a/libguile/variable.h b/libguile/variable.h
index 9b426bc4e..8de09879a 100644
--- a/libguile/variable.h
+++ b/libguile/variable.h
@@ -54,8 +54,8 @@ extern int scm_tc16_variable;
 
 #define SCM_VARVCELL(V) 	SCM_CDR(V)
 #define SCM_VARIABLEP(X)   	(scm_tc16_variable == SCM_CAR(X))
-#define SCM_UDSCM_VARIABLEP(X) 	(SCM_VARIABLEP(X) && SCM_UNBNDP (SCM_CDR (SCM_VARVCELL (X))))
-#define SCM_DEFSCM_VARIABLEP(X) 	(SCM_VARIABLEP(X) && !SCM_UNBNDP (SCM_CDR (SCM_VARVCELL (X))))
+#define SCM_UDVARIABLEP(X) 	(SCM_VARIABLEP(X) && SCM_UNBNDP (SCM_CDR (SCM_VARVCELL (X))))
+#define SCM_DEFVARIABLEP(X) 	(SCM_VARIABLEP(X) && !SCM_UNBNDP (SCM_CDR (SCM_VARVCELL (X))))
 
 
 #ifdef __STDC__