diff --git a/contrib/postgres_fdw/postgres_fdw.h b/contrib/postgres_fdw/postgres_fdw.h
index eef410db39..3364a203c7 100644
--- a/contrib/postgres_fdw/postgres_fdw.h
+++ b/contrib/postgres_fdw/postgres_fdw.h
@@ -77,7 +77,7 @@ typedef struct PgFdwRelationInfo
 	bool		use_remote_estimate;
 	Cost		fdw_startup_cost;
 	Cost		fdw_tuple_cost;
-	List	   *shippable_extensions;	/* OIDs of whitelisted extensions */
+	List	   *shippable_extensions;	/* OIDs of allowed extensions */
 
 	/* Cached catalog information. */
 	ForeignTable *table;
diff --git a/contrib/postgres_fdw/shippable.c b/contrib/postgres_fdw/shippable.c
index 3433c19712..8a3dca9e90 100644
--- a/contrib/postgres_fdw/shippable.c
+++ b/contrib/postgres_fdw/shippable.c
@@ -111,7 +111,8 @@ InitializeShippableCache(void)
  *
  * Right now "shippability" is exclusively a function of whether the object
  * belongs to an extension declared by the user.  In the future we could
- * additionally have a whitelist of functions/operators declared one at a time.
+ * additionally have a list of allowed functions/operators declared one at a
+ * time.
  */
 static bool
 lookup_shippable(Oid objectId, Oid classId, PgFdwRelationInfo *fpinfo)
diff --git a/src/backend/access/hash/hashvalidate.c b/src/backend/access/hash/hashvalidate.c
index 6f14a9fb45..744d22b042 100644
--- a/src/backend/access/hash/hashvalidate.c
+++ b/src/backend/access/hash/hashvalidate.c
@@ -309,7 +309,7 @@ check_hash_func_signature(Oid funcid, int16 amprocnum, Oid argtype)
 		 * that are different from but physically compatible with the opclass
 		 * datatype.  In some of these cases, even a "binary coercible" check
 		 * fails because there's no relevant cast.  For the moment, fix it by
-		 * having a whitelist of allowed cases.  Test the specific function
+		 * having a list of allowed cases.  Test the specific function
 		 * identity, not just its input type, because hashvarlena() takes
 		 * INTERNAL and allowing any such function seems too scary.
 		 */
diff --git a/src/backend/utils/adt/lockfuncs.c b/src/backend/utils/adt/lockfuncs.c
index e992d1bbfc..267fc7adfd 100644
--- a/src/backend/utils/adt/lockfuncs.c
+++ b/src/backend/utils/adt/lockfuncs.c
@@ -632,9 +632,9 @@ pg_isolation_test_session_is_blocked(PG_FUNCTION_ARGS)
 	/*
 	 * Check if blocked_pid is waiting for a safe snapshot.  We could in
 	 * theory check the resulting array of blocker PIDs against the
-	 * interesting PIDs whitelist, but since there is no danger of autovacuum
-	 * blocking GetSafeSnapshot there seems to be no point in expending cycles
-	 * on allocating a buffer and searching for overlap; so it's presently
+	 * interesting list of allowed PIDs, but since there is no danger of
+	 * autovacuum blocking GetSafeSnapshot there seems to be no point in expending
+	 * cycles on allocating a buffer and searching for overlap; so it's presently
 	 * sufficient for the isolation tester's purposes to use a single element
 	 * buffer and check if the number of safe snapshot blockers is non-zero.
 	 */
diff --git a/src/tools/pginclude/README b/src/tools/pginclude/README
index a067c7f472..d1906a3516 100644
--- a/src/tools/pginclude/README
+++ b/src/tools/pginclude/README
@@ -64,7 +64,7 @@ with no prerequisite headers other than postgres.h (or postgres_fe.h
 or c.h, as appropriate).
 
 A small number of header files are exempted from this requirement,
-and are whitelisted in the headerscheck script.
+and are allowed in the headerscheck script.
 
 The easy way to run the script is to say "make -s headerscheck" in
 the top-level build directory after completing a build.  You should
@@ -86,7 +86,7 @@ the project's coding language is C, some people write extensions in C++,
 so it's helpful for include files to be C++-clean.
 
 A small number of header files are exempted from this requirement,
-and are whitelisted in the cpluspluscheck script.
+and are allowed in the cpluspluscheck script.
 
 The easy way to run the script is to say "make -s cpluspluscheck" in
 the top-level build directory after completing a build.  You should
diff --git a/src/tools/pgindent/pgindent b/src/tools/pgindent/pgindent
index 457e328824..06e4d68991 100755
--- a/src/tools/pgindent/pgindent
+++ b/src/tools/pgindent/pgindent
@@ -54,10 +54,10 @@ $excludes ||= "$code_base/src/tools/pgindent/exclude_file_patterns"
 # some names we want to treat like typedefs, e.g. "bool" (which is a macro
 # according to <stdbool.h>), and may include some names we don't want
 # treated as typedefs, although various headers that some builds include
-# might make them so.  For the moment we just hardwire a whitelist of names
-# to add and a blacklist of names to remove; eventually this may need to be
-# easier to configure.  Note that the typedefs need trailing newlines.
-my @whitelist = ("bool\n");
+# might make them so.  For the moment we just hardwire a list of allowed of
+# names to add and a blacklist of names to remove; eventually this may need to
+# be  easier to configure.  Note that the typedefs need trailing newlines.
+my @allowed = ("bool\n");
 
 my %blacklist = map { +"$_\n" => 1 } qw(
   ANY FD_SET U abs allocfunc boolean date digit ilist interval iterator other
@@ -134,8 +134,8 @@ sub load_typedefs
 		}
 	}
 
-	# add whitelisted entries
-	push(@typedefs, @whitelist);
+	# add allowed entries
+	push(@typedefs, @allowed);
 
 	# remove blacklisted entries
 	@typedefs = grep { !$blacklist{$_} } @typedefs;