diff --git a/contrib/pg_standby/pg_standby.c b/contrib/pg_standby/pg_standby.c
index 23f706b21d..031b1b5cd5 100644
--- a/contrib/pg_standby/pg_standby.c
+++ b/contrib/pg_standby/pg_standby.c
@@ -58,7 +58,6 @@ char	   *triggerPath;		/* where to find the trigger file? */
 char	   *xlogFilePath;		/* where we are going to restore to */
 char	   *nextWALFileName;	/* the file we need to get from archive */
 char	   *restartWALFileName; /* the file from which we can restart restore */
-char	   *priorWALFileName;	/* the file we need to get from archive */
 char		WALFilePath[MAXPGPATH * 2]; /* the file path including archive */
 char		restoreCommand[MAXPGPATH];	/* run this to restore */
 char		exclusiveCleanupFileName[MAXFNAMELEN];	/* the file we need to get
diff --git a/src/backend/regex/regcomp.c b/src/backend/regex/regcomp.c
index 8765af71d4..91078dcd80 100644
--- a/src/backend/regex/regcomp.c
+++ b/src/backend/regex/regcomp.c
@@ -288,7 +288,6 @@ struct vars
 #define NWBDRY	'W'				/* non-word-boundary constraint */
 #define SBEGIN	'A'				/* beginning of string (even if not BOL) */
 #define SEND	'Z'				/* end of string (even if not EOL) */
-#define PREFER	'P'				/* length preference */
 
 /* is an arc colored, and hence on a color chain? */
 #define COLORED(a) \
diff --git a/src/backend/storage/lmgr/predicate.c b/src/backend/storage/lmgr/predicate.c
index 2d709420c3..85a629f4fc 100644
--- a/src/backend/storage/lmgr/predicate.c
+++ b/src/backend/storage/lmgr/predicate.c
@@ -364,7 +364,7 @@ static SERIALIZABLEXACT *OldCommittedSxact;
  * These configuration variables are used to set the predicate lock table size
  * and to control promotion of predicate locks to coarser granularity in an
  * attempt to degrade performance (mostly as false positive serialization
- * failure) gracefully in the face of memory pressurel
+ * failure) gracefully in the face of memory pressure.
  */
 int			max_predicate_locks_per_xact;	/* set by guc.c */
 int			max_predicate_locks_per_relation;	/* set by guc.c */
@@ -4809,7 +4809,7 @@ OnConflict_CheckForSerializationFailure(const SERIALIZABLEXACT *reader,
 }
 
 /*
- * PreCommit_CheckForSerializableConflicts
+ * PreCommit_CheckForSerializationFailure
  *		Check for dangerous structures in a serializable transaction
  *		at commit.
  *
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 0c58f1f109..3af8bce206 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -98,7 +98,6 @@
 /* macros to test if pretty action needed */
 #define PRETTY_PAREN(context)	((context)->prettyFlags & PRETTYFLAG_PAREN)
 #define PRETTY_INDENT(context)	((context)->prettyFlags & PRETTYFLAG_INDENT)
-#define PRETTY_SCHEMA(context)	((context)->prettyFlags & PRETTYFLAG_SCHEMA)
 
 
 /* ----------
@@ -115,7 +114,7 @@ typedef struct
 	List	   *windowTList;	/* targetlist for resolving WINDOW clause */
 	int			prettyFlags;	/* enabling of pretty-print functions */
 	int			wrapColumn;		/* max line length, or -1 for no limit */
-	int			indentLevel;	/* current indent level for prettyprint */
+	int			indentLevel;	/* current indent level for pretty-print */
 	bool		varprefix;		/* true to print prefixes on Vars */
 	ParseExprKind special_exprkind; /* set only for exprkinds needing special
 									 * handling */
diff --git a/src/interfaces/libpq/fe-exec.c b/src/interfaces/libpq/fe-exec.c
index 48d4ebdd96..b3c59a0992 100644
--- a/src/interfaces/libpq/fe-exec.c
+++ b/src/interfaces/libpq/fe-exec.c
@@ -3291,7 +3291,7 @@ PQflush(PGconn *conn)
  *		PQfreemem - safely frees memory allocated
  *
  * Needed mostly by Win32, unless multithreaded DLL (/MD in VC6)
- * Used for freeing memory from PQescapeByte()a/PQunescapeBytea()
+ * Used for freeing memory from PQescapeBytea()/PQunescapeBytea()
  */
 void
 PQfreemem(void *ptr)
diff --git a/src/interfaces/libpq/libpq-fe.h b/src/interfaces/libpq/libpq-fe.h
index 26198fc1de..039824196c 100644
--- a/src/interfaces/libpq/libpq-fe.h
+++ b/src/interfaces/libpq/libpq-fe.h
@@ -565,10 +565,10 @@ extern void PQdisplayTuples(const PGresult *res,
 
 extern void PQprintTuples(const PGresult *res,
 						  FILE *fout,	/* output stream */
-						  int printAttName, /* print attribute names */
-						  int terseOutput,	/* delimiter bars */
-						  int width);	/* width of column, if 0, use variable
-										 * width */
+						  int PrintAttNames, /* print attribute names */
+						  int TerseOutput,	/* delimiter bars */
+						  int colWidth);	/* width of column, if 0,
+									* use variable width */
 
 
 /* === in fe-lobj.c === */
diff --git a/src/interfaces/libpq/libpq-int.h b/src/interfaces/libpq/libpq-int.h
index fcf2bc2cab..a0b142b501 100644
--- a/src/interfaces/libpq/libpq-int.h
+++ b/src/interfaces/libpq/libpq-int.h
@@ -232,7 +232,8 @@ typedef enum
 	PGQUERY_DESCRIBE			/* Describe Statement or Portal */
 } PGQueryClass;
 
-/* PGSetenvStatusType defines the state of the PQSetenv state machine */
+/* PGSetenvStatusType defines the state of the pqSetenv state machine */
+
 /* (this is used only for 2.0-protocol connections) */
 typedef enum
 {
diff --git a/src/test/isolation/Makefile b/src/test/isolation/Makefile
index c3c8280ea2..dc22e5ca9d 100644
--- a/src/test/isolation/Makefile
+++ b/src/test/isolation/Makefile
@@ -55,7 +55,7 @@ installcheck: all
 check: all
 	$(pg_isolation_regress_check) --schedule=$(srcdir)/isolation_schedule
 
-# Versions of the check tests that include the prepared_transactions test
+# Versions of the check tests that include the prepared-transactions test
 # It only makes sense to run these if set up to use prepared transactions,
 # via TEMP_CONFIG for the check case, or via the postgresql.conf for the
 # installcheck case.
